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Kindly note that this edition was last substantially edited in 2001 and so some of
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© 1999-2003 Mike G. Eccles, Jane M. Nash & Jean-Paul Van Belle
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This book is copyright under the Berne Convention.
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DEDICATIONS
To my parents, Roger and Monique
for showing me how to live
And to my own family
Eva, Anneke, Jonathan and Sylvia
For showing me why to live
JPVB
To my wife Stella
For being such a wonderful person
ME
To my students of the past, present and future
JN
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TABLE OF CONTENTS
Foreword i
Why Study Information Systems? i
The Importance of Information Systems ii
Information Systems and Related Disciplines ii
Contents of This Book iii
Section I: What is "Information Systems "? 1
1. The Role of IS in Business 2
1.1 Classification of Information Systems 2
1.2 Office Automation Systems (OAS) 5
1.3 Groupware 6
1.4 South African Perspective 8
1.5 Beyond the Basics 8
1.6 Exercises 9
2. Transforming Data into Information 10
2.1 Data 10
2.2 Information 16
2.3 Knowledge and Wisdom 18
2.4 Producing Business Information 19
2.5 South African Perspective 20
2.6 Beyond the Basics 20
2.7 Exercises 21
3. How Systems Function 22
3.1 What is a System? 22
3.2 Elements of a System 23
3.3 Systems Concepts 26
3.4 South African Perspective 29
3.5 Beyond the Basics 29
3.6 Exercises 30
CASE STUDY: GREENFINGERS GARDEN SERVICES 31
Section II: IS Technologies 33
4. Hardware 35
4.1 Input devices 35
4.2 Central Processing Unit (CPU) 39
4.3 Main Memory 42
4.4 Secondary Storage Devices 43
4.5 Output Devices 46
4.6 South African Perspective 50
4.7 Beyond the Basics 50
4.8 Exercises 50
5. Software 52
5.1 The User Interface 52
5.2 Application Software 55
5.3 System Development Software 56
5.4 Operating Systems 62
Discovering Information Systems
5.5 South African Perspective 64
5.6 Beyond the Basics 64
5.7 Exercises 65
6. Networks & Telecommunications 66
6.1 Computer Networks 66
6.2 Telecommunication Devices 67
6.3 SA Public Telecommunications Services 69
6.4 The Internet 70
6.5 South African Perspective 75
6.6 Beyond the Basics 75
6.7 Exercises 76
7. Databases 77
7.1 From File-based Systems to the Database Approach 77
7.2 Data Structures 79
7.3 Database Models 81
7.4 Database management 84
7.5 Database Architectures 85
7.6 South African Perspective 87
7.7 Beyond the Basics 87
7.8 Exercises 88
CASE STUDY: GREENFINGERS GARDEN SERVICES 90
Section III: IS Applications 91
8. Business Support Systems 93
8.1 The Decision-Making Process 93
8.2 Batch vs Online Processing 94
8.3 Applications at Different Management Levels 95
8.4 Strategic Systems 98
8.5 Intelligent Systems 99
8.6 Data Mining and OLAP 100
8.7 South African Perspective 102
8.8 Beyond the Basics 102
8.9 Exercises 103
9. E-Commerce 104
9.1 B2C e-Commerce 104
9.2 B2B e-Commerce 105
9.3 C2C e-Commerce 106
9.4 Electronic funds transfer 106
9.5 Current issues in e-commerce 107
9.6 South African Perspective 108
9.7 Beyond the Basics 108
9.8 Exercises 109
10. Security and Social Issues 110
10.1 Security Within the Organisation Ill
10.2 Security Beyond the Organisation 113
10.3 Operational Problems and Errors 115
10.4 Computer Monitoring and Privacy 116
10.5 Computers and Unemployment 118
10.6 South African Perspective 119
10.7 Beyond the Basics 119
Discovering Information Systems
10.8 Exercises 120
CASE STUDY: CREAM ADVERTISING 122
Section IV: IS Management 1 24
11. IS Planning & Acquisition 125
11.1 Frameworks for Analysing Information Systems 125
11.2 IS Planning 127
11.3 Software Acquisition Options 128
11.4 Project Management 129
11.5 People Aspects of Systems Development 131
11.6 South African Perspective 132
11.7 Beyond the Basics 132
11.8 Exercises 133
12. System Development 134
12.1 Systems Development Life Cycle (SDLC) 134
12.2 Development of Structured Methodologies 140
12.3 Alternative approaches to developing systems 142
12.4 Critical success factors 146
12.5 South African Perspective 146
12.6 Beyond the Basics 147
12.7 Exercises 147
13. Using Information Systems 149
13.1 Change Management 149
13.2 Ergonomics 150
13.3 Ethics 150
13.4 Data Processing Controls 152
13.5 Disaster Recovery 152
13.6 How IS Affects You 153
13.7 South African Perspective 154
13.8 Beyond the Basics 154
13.9 Exercises 155
CASE STUDY: CREAM ADVERTISING 156
INDEX 157
Discovering Information Systems
Foreword
Why Study Information Systems?
Why did you enrol for this course in information systems? It is probably a mix of pragmatism
and idealism. For many of you, this course is not an elective, so you have to endure and pass
it in order to obtain your degree. On the other hand, many of you chose to study this degree,
and perhaps even selected information systems as a major. This choice was probably inspired
by practical considerations such as the desire to have at least a reasonable fighting chance on
the job market a couple of years from now, and the hope of earning the typical above average
salary which graduates with an "IS" course (or better even: IS major) on their academic
record tend to earn. But hopefully, you also have some interest in and positive expectations
about this course. You may already have quite a bit of exposure to computers, be it from
hacking away on the Internet or playing Doom. And you have definitely already encountered
information systems in many different areas of your lives : they may have been responsible for
the late publication of your test results, your (in-)ability to withdraw money from the ATM, or
they enabled you to get great marks for your school projects.
Unfortunately, we cannot promise that this course will make you better Doom or PacMan
players. (We are not very good Doom players ourselves.) But we do hope to keep at least
some of the fun and excitement in the course. Let us give you some motivation for giving this
course an extra effort.
• Money. IS graduates are amongst the best paid of all graduates. In fact, to our
annoyance, many of our graduates walk into a job with a higher starting salary than
we, their lecturers, earn after many years !
• Importance. University graduates must expect to work in an environment where
information systems play an important, if not critical, role in their day-to-day
activities. The ability to use personal productivity tools, and a working knowledge of
the fundamental concepts underlying today's, and more importantly, tomorrow's
information systems, are no longer "nice to have" skills from a career perspective:
they have become essential minimum requirements.
• Change and dynamism. Unlike many other academic disciplines, the pace and rate
of change in our field is extremely fast. You will already be familiar with the rate at
which the computer and communication technologies are changing, perhaps best
illustrated by how quickly personal computers become out-dated. But many of our
(academic) theories, views and commercial practices also have to be revised on an
almost annual basis. As a young science, we constantly have to re-examine our body
of knowledge. This continuing renewal may scare off the casual-type persons, but it
should excite people like you: dynamic, energetic and thriving on change.
• Fun and challenge. In our most humble opinion, there is more fun and challenge to
be had in IS than in all other disciplines combined. (Hmm, maybe we do sound a tiny
bit biased here!) In building up your skills in the literacy component, you will be
challenged to discover new tricks and short-cuts all the time. You may have to push
yourself to the limit to cope with the amount of power and capabilities presented to
Discovering Information Systems
you by the software. But also in the more conceptual sections, we hope that this will
be the one course where you will have to use some critical thinking skills and, above
all, accept that there is no one correct solution to each question. In fact, we often do
not yet know what the right question to ask is.
If you delve a little deeper in the curricula vitae of the academic staff in the department, you
will notice that many of your lecturers have non-IS backgrounds: accounting, engineering,
management, or even the liberal arts. What made them change was (typically) not boredom
with their original fields of endeavour but the excitement, change and dynamism that comes
with information systems. We hope that you will discover this for yourself and share some of
our excitement !
The Importance of Information Systems
Since many of you may have had limited exposure to the way large organisations work, the
following facts may be of interest:
• Globally, the annual capital (fixed) investment in information technology (computers,
telecommunications) currently exceeds the investment in all other productive capital
assets (buildings, equipment, machinery, tractors etc.) combined.
• In the developed countries, more than half of the labour force can be classified as
knowledge workers i.e. it spends most of its time processing information.
• The amount of new knowledge is said to double every five years i.e. in the next five
years we will create as much new knowledge as was created in mankind's entire
previous history. (The quality of this new knowledge is of course an entirely different
issue!)
•
•
• Each month the equivalent processing power of one of the early personal computers
(half a million microchip transistors) is being produced for each human on the entire
planet.
The information systems of many large organisations would be able to store and
process the curriculum vitae of every single human being that lives and ever lived on
the Earth, assuming that this information was available in electronic format.
Four years after graduating from UCT, Mark Shuttleworth sold his IT business for a
billion rands - sufficient to generate an hourly income of about R30 000!
Information Systems and Related Disciplines
IS, which is normally considered one of the commercial sciences along with management and
accounting, has its "cousins" in the other major groups of scientific disciplines.
• Computer Science, typically part of the natural and exact sciences such as (applied)
mathematics, is concerned with the scientific basis of software and hardware
technologies which underlie information systems: computers and communications.
Sample research areas include computer architectures, programming languages,
efficient algorithms, artificial intelligence, computability, etc. These, together with
innovative electronic engineers and material scientists, are often responsible for
[Free reproduction for educational use granted] © Van Belle, Eccles & Nash
•
fundamental advances in the technology and are usually five to ten years ahead of the
commercial application of these technologies. However, they tend to pay far less
attention to the organisational and human context in which computers are used e.g.
market viability, cost, project management, system effectiveness, organisational
change management. Computer science also has little to say about non-computerised
information systems, though this also applies to many information systems curricula
and research agendas.
Information Science has grown out of library science, typically considered part of the
liberal arts discipline. It is far more philosophical in approach than computer science
and information systems. Many of its findings apply equally well to computer and
non-computer based systems alike. The main emphasis is on the storage and retrieval
in large databases (libraries) of information. This includes issues such as
classification, indexing, abstracting.
If the above gives you the impression that there is little overlap between the fields, we have to
state that the converse is in fact true. There are many overlapping fields of research and
undergraduate curricula often cover similar topics. (This sometimes results in some
demarcation or "turf disputes, despite the fact that "some of our best friends are computer
and information scientists!") On the other hand, each discipline has its own perspective on
even the most common topics of interest. IS has a very strong organisational bias, usually
taking the commercial business enterprise as the implicitly assumed context of our studies.
This is reflected in research into project management, procurement issues, audit and control
principles, management issues, IS professionals' profiles and the like.
Rather than looking at undergraduate syllabi, a good feel for the differences in scope and
emphasis between the disciplines can be obtained by browsing some of the prominent
scientific journals of each discipline.
Contents of This Book
This text consists of thirteen chapters, which have been grouped into four sections:
• What is Information Systems? These three chapters describe the role of information
systems in modern organisations, and explain the underlying concepts of
"information" and "systems" in some detail.
• IS Technologies. These four chapters provide an overview of the basic technologies
that are found in all computer-based information systems: computer hardware,
software, communications systems and databases.
• IS Applications. These three chapters examine in some detail how information
systems are used to support and enhance business processes, at all levels of the
organisation and in linking organisations with their customers and suppliers. We also
consider some wider societal concerns such as ethics.
•
IS Management. An information system does not simply appear out of nowhere; it
needs to be planned, developed and maintained using well tested management
Discovering Information Systems iii
principles. Issues ranging from software and hardware acquisition to disaster recovery
are discussed in these three chapters.
You should not see this text in isolation from the practical worksheets, case studies, videos
and group work that will be provided in the lectures. The intention of these additional
materials is to enhance the educational process through participatory learning units: as you
know, you learn best when doing.
It is also our conviction that university students need to be introduced from the first year to
academic pluralism: too often undergraduate students are given the impression that there is
one single correct approach or, even worse, that most problems have one and only one correct
solution. You may therefore be asked to locate and discuss additional readings related to
concepts covered in this book, which will expose you to alternative views on the course
material.
iv [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I What is "Information Systems"?
Section I: What is "Information Systems"?
Welcome to our world: the world of information systems (IS). It is an exciting world where
the borders change daily, the landscapes vary dramatically, the limits go far beyond the skies
and many places have hardly been explored. In fact, most of our world is still uncharted
territory. Fun is to be found around almost every little corner, often just across the road from
those other big corners where frustration is lying aplenty.
You may have chosen IS as your major, or have had it imposed on you by your curriculum;
you may be looking forward to the challenges it will present, or regard it as a hurdle to be
overcome. Either way, it's important to begin with an understanding of what you can expect
from the subject, and what the subject will expect from you.
IS is not simply about computers - it's about how businesses can make the best use of
computer technology to provide the information needed to achieve their goals. In the same
way as your own needs and priorities are unique to you, each organisation has different goals
and requirements, and the successful implementation of IS requires a through understanding
of the business issues involved, as well as the different technologies that are available. Most
of the time there is no single "correct answer", and you will need to draw on your own
knowledge and judgement when planning or using an information system. The purpose of this
introductory course is to provide you with a basic knowledge of the different elements of
information systems: the building blocks that can be combined in a variety of different ways
to suit particular business needs.
Perhaps the best way to illustrate the importance of IS, is to consider the impact that it has on
your own life. Try to imagine what your daily life would be like without information systems :
you might be able to survive without your student fee account, but can you also imagine no
television, no cellphone, no fax, the end of mass air travel as we know it, the collapse of the
banking system ...? Most of our lives would be affected dramatically. Now stop to consider
the times that you have been irritated or frustrated by the inefficiency of a large organisation
(Home Affairs? University registration?), and you will see that technology alone is not the
solution to business problems - computers are simply one element of a complete system
intended to support the flow of information within a business environment.
This first section of this textbook briefly examines the different roles played by IS in
organisations, and explains the basic concepts of a system and of information, which underlie
all information systems.
Discovering Information Systems
1. The Role of IS in Business Section I
1. The Role of IS in Business
Businesses make use of information systems so that accurate and up-to-date information will
be available when it is required. Since it is not always possible to predict what information
will be needed at some future date, most organisations use computers to record and store the
details of all their business transactions. When a query arises, or a standard business report
must be produced, this raw data can be retrieved and manipulated to produce the required
information.
An employee may want to know how much leave he has due, a customer may enquire
whether an item is in stock, financial statements must be produced for shareholders. Because
the methods and calculations used in processing the employee payroll are very different from
those used for managing stock control or for preparing a balance sheet, you will usually find
that a number of different application programs are used within a single business. These
application programs, plus the computer equipment that they run on, and the data that they
use, must together meet the information requirements of the organisation, and their integration
must be carefully planned to ensure that all aspects of the business are supported as efficiently
as possible.
1. 1 Classification of Information Systems
Within any single organisation, executives at different levels in the management hierarchy
have very different information requirements, and different types of information systems have
evolved to meet their needs. A common approach to examining the types of information
systems used within organisations, is to categorise IS applications by the roles they play at
various levels in the organisational structure - this is known as the vertical approach. In this
case the organisation is viewed as a management pyramid with four levels:
• At the lowest level, non-management staff attend to routine daily business
transactions such as selling goods and issuing receipts for payment.
• Operational management are responsible for monitoring the transactions that are
occurring, and dealing with any problems that may arise.
• Tactical management decide on budgets, set targets, identify trends and develop short
term plans for the business.
• At the top of the pyramid, strategic management is responsible for defining the long
term goals of the company, and how it intends to position itself within its particular
industry.
These levels of management correspond approximately to four different types of information
systems (see Figure 1-1).
1.1.1 Transaction Processing Systems
At the lowest level of the organisational hierarchy we find the transaction processing
systems (TPS) that support the day-to-day activities of the business. These applications are
normally the first to be computerised and are characterised by large numbers of transactions
[Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I
1. The Role of IS in Business
updating the corporate database. These systems are mainly used by clerical staff performing
such regular business activities as invoicing and issuing of stock, following well defined
business procedures. The users of transaction processing systems tend to work at the lowest
level of detail as they process or query one transaction at a time, using computer systems to
capture the raw data which reflects the business processes of the organisation. For example,
the itemised till slip from a supermarket is produced by the TPS, and details of each
individual item sold will be recorded in the store' s database.
Executive
Information Systems
> Decision Support Systems
&
IVfenagement Information
> Systems
Transaction Processing
Systems
Figure 1-1: Levels of management and types of support systems
1.1.2 Management Information Systems
The next level in the organisational hierarchy is occupied by low level managers and
supervisors. This level contains computer systems that are intended to assist operational
management in monitoring and controlling the transaction processing activities that occur at
clerical level. Management information systems (MIS) use the data collected by the TPS to
provide supervisors with the necessary control reports. For example, in a debtors system, the
individual responsible for collection of unpaid accounts could extract a listing from the
computer of customers whose accounts have been outstanding for more than three months. At
this level, output reports generally contain summarised totals of the TPS data, produced either
on a cyclical basis (weekly or monthly) or on request. Additional reports include control
listings, where totals are balanced between processing runs to ensure that data has not been
lost or fraudulently manipulated, or exception reports, where the computer selects and reports
only on unusual transactions that need to be reviewed by management. The main focus of
MIS is to avoid wading through huge volumes of detailed data, instead using control totals
and exceptions to identify problems.
1.1.3 Decision Support Systems
Tactical management occupies the next level in the organisational hierarchy. These managers
are responsible for ensuring that plans and targets set by senior management are achieved.
They tend to focus not on the progress of individual transactions but on the bigger picture -
for example the relative sales performance of different sales areas in the organisation. To
achieve this they need to receive regular reports from the MIS with summary totals and
comparison between prior months and years, or planned activity levels. Where summary
figures are of concern, these managers may request more detailed reports from the operations
Discovering Information Systems
1. The Role of IS in Business Section I
personnel.
However there is also a new requirement for information from this level of management. In
many cases problems arise and additional 'ad hoc' reports are needed. Perhaps the sales
figures for the Cape Town region are below the annual year-to-date forecast and management
needs to investigate where the problem lies. Analysis of the monthly sales information in the
database may reveal the answer. For example it could be poor sales performance by a retail
outlet or salesman, loss of a major customer or lack of demand for a particular product. Often
problems arise that require management to look at data in the database from a new or different
perspective. This particular information requirement may not have been identified when the
computer application was developed and therefore no standard report is available to
management.
In the past the IS department received regular requests for selected information to be extracted
from the database for presentation to management. Many organisations have recognised the
importance of this type of information need, and have implemented sophisticated user driven
decision support systems (DSS) which allow managers to generate their own reports and
enquiries. When information is required to support management decision making, the user is
able to interact directly with the computer via a graphical user interface to request the relevant
data, select and apply the appropriate decision model and generate the output report in the
format required.
1.1.4 Executive Information Systems
The highest level in the organisational structure is that of strategic management, and once
again its information requirements are unique. These managers are charged with the task of
setting the strategy for the organisation. They require an information system that will enable
them to identify problems, opportunities and trends that may enhance or threaten their
organisation's competitive position.
In the early days of commercial computing, top management spent much of its time wading
through reports relating to the performance of strategic areas of the business. In order to
reduce the time taken in finding and integrating a few critical numbers from many different
reports, the concept of the executive information system (EIS) was developed. Top
executives identify particular indicators that best measure business performance in critical
areas of the business. Data relating to these indicators, as well as information about competing
companies and the overall business environment, is collected, analysed and presented (usually
in a graphical format). If a problem is identified by top management, then the EIS provides
the facility to drill down to a lower level of detail in the database to obtain a better
understanding of the problem and its causes.
The following table (Figure 1-2) summarises the major differences between the four levels of
organisational support systems based on their major inputs, processing characteristics and
outputs:
[Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I
1. The Role of IS in Business
Management
Level
Applications
Support
Inputs
Processing
Outputs
Clerical
Transaction
Processing
System
Detailed
transactions
Transaction
updates
Detailed reports
Operational
documentation
Operational
Control
Management
Information
System
Operational data
Selection
Summarisation
Reconciliation
Summary and
Exception reports
Tactical
Decision
Support
System
Operational data
& Decision
models
Simulation
Analysis
Ad hoc reports
Strategic
Executive
Information
System
Internal and
External data
Summarisation
Drill down
Critical Success
Indices
Figure 1-2: Characteristics of each level of management support
1.2 Office Automation Systems (OAS)
Other types of information systems are not specific to any one level in the organisation but
provide important support for a broad range of users. Many standard computer applications,
such as word processing, spreadsheeting, data management, and presentation graphics are
used across all management levels of the organisation. Apart from their individual
capabilities, many of these programs are able to exchange information, so that for example a
word processing document may include a graph developed using a spreadsheet program,
which is dynamically updated when the data in the spreadsheet is changed.
Word processing software is used to create and maintain electronic documents. Because
word processors create virtual (electronic) documents as opposed to physical ones, any errors
or alterations can be made to the document before it is printed. This simple concept has
empowered all the one and two fingered typists of the world and made the professional typist
an endangered species. More than 90% of all white collar workers in the USA now use a word
processor to perform their jobs; however, as personal computers and word processing
packages become more powerful, so users continually need to update their skills to get to
grips with the next generation of software.
Spreadsheets are to numbers what the word processor is to text. They allow for easy
preparation of financial statements, cash flows, budgets and other problems requiring
quantitative analysis. The beauty of the electronic spreadsheet is that it mirrors the way we
performed the task manually, except that users enter data via a keyboard and view it on a
computer screen rather than writing on to paper. This similarity ensures users understand and
become proficient in the use of spreadsheet packages in a very short period of time. Because
of their ability to use formulas and functions to recalculate answers when values are changed,
spreadsheets are excellent tools for performing "what if analysis. Today's spreadsheet
packages also offer a variety of statistical and business analysis tools, together with the ability
to generate business charts directly from the spreadsheet data.
Data management software is used to create and maintain records about items such as
Discovering Information Systems
1. The Role of IS in Business Section I
customers, stock or employees, which are vital to the operation of any business. The main
advantage of automation when applied to organisational record-keeping, is the power of the
computer to select, sequence, summarise and report on data once it has been captured. In
addition, data management software incorporates error-checking features, which could ensure
for example that only valid account numbers may be entered in a transaction, and
sophisticated backup and retrieval methods. Traditionally, data management has been
regarded as the most difficult of the office automation applications, and is used mainly by
those with specialised skills. There are, however, a number of simple data management
facilities in most word processing and spreadsheet packages, such as the ability of word
processing programs to perform mail merges in which a standard letter is merged with
personal information from a database.
Presentation graphics software provides an easy means of generating high quality
presentation materials based on colour overheads, slides or large screen displays. The latest
versions include advanced slide show facilities together with animation and sound clips. This
has become a popular tool for marketing, executive reporting, training and seminars.
1.3 Groupware
Most office automation applications are designed for standalone users although the data and
information can be shared through the use of networks and e-mail. However, much of the
work performed in business today is cooperative with individuals working together in groups
to achieve common goals. Groupware is the term given to software developed to support the
collaborative activities of work groups, with typical requirements being information sharing,
electronic meetings, scheduling and e-mail.
Groups are often informal and could include members of a project team, employees within a
department, or individuals with a common interest. Normally an individual is included in a
number of groups, each with a specific focus. For example a lecturer in the accounting
department would probably be included in the staff group (university wide), accounting
department group, lecturers group (university wide), accounting lecturers group, Accounting
II group (which he co-ordinates), accounting research group (international) and so on. Mail
and discussions can be focused by means of a particular group name which addresses all its
members. As long as the groups are kept up to date as members change careers and interests,
addressing 2,500 co-workers can be as easy as addressing a single individual.
Apart from the obvious e-mail communication, there are a number of other group activities
supported by current software.
Where individuals are encouraged to maintain an electronic calendar detailing their
appointments and availability, groupware can search through the calendars to find times when
all members of a group are available (for example when a staff meeting needs to be
scheduled) and makes the required entry in each individual's diary.
The use of compound documents makes it easier to circulate files among the members of a
group and keep track of changes that are made. Many office products allow some integration
of files from a number of different systems, so that part of a spreadsheet for example can be
[Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I 1. The Role of IS in Business
embedded in a word processing document. However some groupware products (such as Lotus
Notes) go further and create a database for each communication where any combination of
documents can be combined for distribution around the group. Another useful feature of
groupware documents is the ability to control group editing and update, by allowing
colleagues to attach comments to the document without altering the original text. In addition,
in cases where criticism is required and even encouraged, the system can also allow for the
group input to be anonymous.
Project management software provides graphical tools to help manage projects by
sequencing tasks, allocating and scheduling resources and reporting on project progress. Files
can be checked in and out by members of the project team, changes are tracked using version
control, and project managers can use "what if queries to assess the impact of changes in the
use of resources or time.
Electronic meeting software is designed to support interaction between members of a
distributed group, without the cost and time wasted through travelling to a physical
destination. Here groups can log into an electronic meeting from their offices or in special
purpose electronic meeting rooms. While the meeting can be conducted by typed
communications between the recipients, voice and even video communication can also be
included. Apart from providing the means of communication, groupware can also store the
output of such sessions in electronic format to assist with documentation and analysis of the
group input. In the past, video-conferencing facilities were expensive but today multimedia
upgrades can be installed on local machines at low cost. The one bottleneck to this groupware
functionality is the quality of communications between the participants as video
communication requires relatively large volumes of data to be exchanged.
Electronic mail, commonly referred to as e-mail, can be defined as the electronic exchange
of messages between users. Where a user has the required software and links to the internet
(for mail dispatched to remote locations), he or she can enter a message into the computer and
transmit it to the recipient's Internet address. The message is then transferred across the
network and stored on the network server in the recipient's mailbox from where it can be
retrieved. E-mail facilities allow users the ability to print out messages, forward them to third
parties and store mail in appropriate folders for future reference. In addition e-mail has a
number of advantages over the traditional "snail mail" system. Mail can travel to anyone
connected to the Internet in a very short time. It is simple to set up mail groups so that a
number of individuals can communicate about common issues. Files can be attached to e-mail
transmissions, so any material in electronic form can be communicated across the internet.
E-mail is also useful for inter-office communication. Often colleagues are busy or unavailable
when you need to pass on information or discuss a problem. Leaving an e-mail message in the
appropriate mailbox will achieve the required communication without the irritation and stress
of attempting to make verbal or face to face contact. Nevertheless, e-mail communications do
have their limitations. For those who type slowly, entering a long communication can be an
arduous task. In addition e-mail is not as confidential as most users would like, since
organisations may monitor and even open their employees personal e-mail documents.
Discovering Information Systems
1. The Role of IS in Business Section I
1.4 South African Perspective
Automation of data capture and business processes can lead to improved management
information, employee empowerment and customer satisfaction.
• By redesigning their processes for extracting customer data and printing TV licence
statements, the SABC has cut their statement production time from 15 to 7 days,
resulting in reduced costs and faster revenue collection.
• Spur Steak Ranches recently commissioned a new Human Resource system that will
allow staff to check their leave balances and apply for leave on-line.
• And ABSA Bank will soon be building a new call centre in Auckland Park, which
will use sophisticated IT to enable advisors to deal with multiple queries from the
same customer, and allow supervisors to design duty rosters based on trends in service
demands.
However, a word of warning comes from Arthur Goldstuck, commenting on the South
African Government's plan to adopt an IT system that will provide a single gateway to all
state information and services, including a toll-free information centre operating in all 11
official languages (Intelligence magazine, November 2002). Goldstuck points out that
existing services are inadequate at most government outlets, such as Home Affairs, the
Labour Department and the Welfare Department. Investing in technology is not likely to
make a significant improvement to customer service, unless at the same time the attitudes of
staff can also be changed. "If an organisation's workers regard the people they serve as
annoyances, they will keep treating them as annoyances, regardless of the systems that are put
in place." His conclusion: if you want to use technology to streamline a process, first make
sure that the process works.
1.5 Beyond the Basics
All too often, information systems are developed in order to automate existing business
processes. But what happens if those existing processes are inefficient? Increased processing
speed may simply increase the rate at which problems occur. This is where the concept of
business process reengineering (BPR) enters the picture. BPR involves the fundamental
redesign of an organisation's business activities, in order to achieve dramatic improvements
in quality, cost and speed. This is a major undertaking, which must be carefully managed to
avoid employee resistance, since it often involves restructuring of the entire organisation.
However, the benefits of BPR can be enormous. For example, IBM Credit Corporation
reduced the turnaround time for approving credit orders from seven days to four hours by
reengineering the credit approval process so that it could be handled by a single employee
using a decision support system instead of forwarding the credit application through four
different departments.
Trivial fact: T J Watson, the founder of IBM, was once asked how many computers he
expected to sell worldwide, and his answer was 5. There are now over 34 million desktop
computers sold worldwide every year!
8 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I 1. The Role of IS in Business
1.6 Exercises
1.6.1 Organisational Information Systems
Consider the example of a large supermarket chain such as Pick 'n Pay.
•
Identify a typical activity that would be recorded using the Transaction Processing
System. How often would such an activity occur, and what member of staff would be
responsible for recording it ?
• Operational management is responsible for monitoring routine daily activities.
Suggest a regular weekly report that might be produced by the MIS, which includes
information based on the activity you have just identified. Can you think of a
situation in which this activity might be included in an exception report, in order to
draw attention to a potential problem ?
• Tactical management are responsible for forward planning, based on a combination of
MIS reporting and forecasting with the aid of a DSS. What sort of decision about
future business operations might incorporate information about the activity you
originally defined ?
• Strategic management make use of external as well as internal data in developing
long term business strategies. What examples of external data might be relevant to the
strategic planning of a supermarket chain ?
1.6.2 Using Corporate Information
Make a list of all the different organisations that are likely to have recorded your personal
details (UCT, sports club, cellphone company, hospital, school, church etc).
• In what ways could this information have been useful in monitoring the (past)
activities of the organisation?
• In what ways could this information be used for future planning?
Discovering Information Systems
2. Transforming Data into Information Section I
2. Transforming Data into Information
In everyday speech, we do not always draw a clear distinction between the terms "data" and
"information", but the difference between the two is vital to the understanding of what IS is
all about. Data is a collection of raw facts, each one of them insignificant when viewed in
isolation. The purpose of an information system is to process that collection of raw facts in
some way, so as to produce information that is useful to somebody.
For example, if the telephone directory contained a random assortment of names, addresses
and telephone numbers, in no particular order, and with no logical association between names
and phone numbers, it would be of no use to anybody. The facts (data) might all be present,
but the information value of such a directory would be worthless. By associating each phone
number with the name of the corresponding subscriber, and by sorting the list in alphabetical
order of surname, information is produced. This helps to illustrate the inherent complexity of
any information system - first you need to define what purpose it is going to serve (i.e. what
information you want to produce), then you need to identify what data will be required in
order to generate that information, work out how the data will be captured, how it will be
stored, how it should be processed to get the desired result, and how the resulting information
should be communicated to the person needing it.
Viewed in this way, we can see that data and information have very different characteristics.
2.1 Data
Since facts are about something, data refers to some outside object, event or concept. Data
does not necessarily have to refer to a physical object: it can be about concepts (I think
therefore I am a thinker; my bank balance is R4321.01 in debit), relationships between objects
(I live in Oubord vol water), etc. but it does pertain to an objective real world "out there" which
the information system seeks to describe or model. Often the data model is an incomplete
model since we are usually just interested in certain aspects of the real world. Alternatively, a
complete model may consume too many resources or not be practical.
It follows logically that facts or data have a truth-value. They are true if they reflect the state
of the outside world accurately. Of course, they can also be. false, as is the case in the last two
statements. Sometimes, it may not be possible to check the truth-value; in this case, the truth-
value of the data element may be ambiguous.
Also, data has to be represented somehow. This representation can take one of many forms,
all of which boil down to some particular structuring (pattern) of matter or energy. You have
one example in front of you: this sentence consists of shapes made up of black ink particles
on a white sheet of paper ! (It can also be dark grey on light grey, depending on the print and
paper quality.) We will discuss the representation issue in more detail later.
The fact that data is represented in a matter or energy form leads to another characteristic of
data: it is encoded using a specific symbolism and the data can be understood only if one
knows how to decode it. The symbolism can be a certain language and its written alphabet, a
10 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I 2. Transforming Data into Information
digital (numerical) representation of sound frequency (compact discs), the colour and shape of
flags (ship-to-ship visual signalling) or any other agreed code. Often many different options
exist depending on need: an English message could be spoken or "signed" in sign language,
written using the "normal" alphabet or in shorthand, in Braille, in Morse code, in bar code etc.
A final characteristic of data is that it can often be structured quite easily into a standard
format and grouped into large sets of similar data items, especially in organisational contexts:
address lists, customer records, inventory details, personnel records.
2.1.1 Representing Data
Data can exist only if it is encoded using some form of structured matter or energy. The actual
physical encapsulation (in matter or energy form) of the data is its storage medium. The
following are just some examples of how data can be represented.
Ink particles on a piece of paper or other material (book, packaging, T-shirt logo,
graffiti)
Polystyrene lettering or logos on a promotional in-store display board
Needle pins on a city map (indicating e.g. locations of recent robberies)
Magnetic polarisation of suitable materials (music tapes, floppy diskettes)
Light pulses through air or glass fibre (flashing lighthouse, laser light in optical fibre)
Electronic pulses through copper, etc.
The way that data is represented within a computer system, is dictated by the fact that the
basic electronic circuit inside a computer can usually manage only two different states: ON or
OFF, i.e. either electricity is flowing or it is not; or, depending on which circuit we are
discussing, it either holds an electrical charge or it does not. This is why computers are called
binary: they can work only with two values ("bi" means two as in bicycle: two wheels). The
ON and OFF state can represent, depending on convention, a "Yes" or a "No"; a "True" or a
"False"; a "0" or a "1". Or, in fact, anything else that could be coded using only two discrete
values: positive/negative (numbers), white/black (printing), open/closed (switch), in/out of
stock, registered or not, pass/fail etc. In this sense it can be said that computers can count
only... one ... two!
Anything that can be encoded using only a single one of these simplistic "On/Off electronic
circuits is said to consist of one bit of information. The word bit is allegedly derived by
contracting the term "binary digit" because computer scientists usually represent these two
states by means of the two digits 0 and 1 .
A bit is the smallest unit of information, everything less than a bit is nothing! Unfortunately,
most data is far more complex than "Yes/No". But, amazingly, even the most complex
information can be represented using these simplistic binary circuits.
2.1.1.1 How Computers Store Numbers
We are all familiar with the decimal numbering system, based on the number 10. In this
Discovering Information Systems 1 1
2. Transforming Data into Information Section I
system, the available digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9, i.e. for every number position,
there are 10 possible options. Numbers consisting of multiple digits are computed based on
powers of 10. For example, consider the number 4075. The value of this number is computed
in the following way (from right to left):
5x1 + 7x10 + 0x100 + 4x1000 = 4075
Since computers are inherently based on the idea that their components are either on or off,
this is usually represented in terms of binary numbers, where all digits are either 1 or 0. This
means that for every number position there are only two options, 0 or 1. Numbers consisting
of multiple digits are computed based on powers of 2 (since there are only two possible
options for each position). For example, consider the number 11001. The value of this binary
number in decimal terms would be computed in the following way (from right to left):
lxl + 0x2 + 0x4 + 1x8 + 1x16 = 25
In decimal numbers, each "column" is 10 times the column to its right, so from right to left
we have units, 10s, 100s, 1000s, etc. With binary numbers, each column is 2 times the column
to its right (because a column can hold only two possible values, 0 or 1), so instead we have
units, 2s, 4s, 8s, 16s, 32s, etc.
Thus to translate a decimal number into binary format, so that it can be stored and processed
by a computer, we need to determine how many 32s, 16s, 8s, 4s, 2s and Is the decimal
number contains, and indicate the presence or absence of each of these by using a 1 or 0 in the
correct column position. For example, the decimal number 43 consists of a 32, no 16, an 8, no
4, a 2 and a 1 (32+8+2+1=43), and would be represented in binary as 101011. In practice,
numbers are usually represented in groups of at least 8 bits; and more commonly, 32 bits are
used to allow for the storage of extremely large numbers.
2.1.1.2 How Computers Store Text
Much of the data in which people are interested does not consist of numbers but rather of text
e.g. names, addresses, descriptions and sentences such as "The Bulls have won the match!"
Any piece of text is composed of a collection of alphanumeric symbols: letters, punctuation
marks and spaces. Our roman alphabet letters (both upper and lower case), the digits 0 to 9,
the punctuation symbols as well as a number of "special symbols" which are commonly used
in text such as the $ or the %, together add up to about 100 different characters. Since we
already have a way of storing numbers in binary form, it is a simple matter to just assign a
number to each of the characters we wish to represent. There are indeed a number of
international standards for this: EBCDIC and ASCII are the two most common ones. Text is
therefore commonly represented in a computer using bit sequences, which represent the
numbers of the various characters which make up the text, according to some standard list of
character codes. Although 7 bits would be sufficient to store up to 256 different binary codes,
for technical reasons it turns out that it is easier to use groups of 8 rather than 7 bits; so text is
usually stored in computers by encoding each character of the message in "clumps" of 8 bits.
These sets of 8 bits are called bytes. Our "The Bulls have won the match!" sentence therefore
would be represented by a sequence of 29 bytes.
12 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I
2. Transforming Data into Information
Two notes to round off this section:
• As computers are being used in many countries that do not use Roman characters, the
standard set or list of characters is being enlarged to include many more characters.
This means that more bits are required to code each character (e.g. 2 or 4 bytes or
16/32 bits in Unicode). Do you understand why?
• Some of you may by now have realised that there is another method of storing
numbers. Since a number can be written out in decimal form (as in "12876"), it is
possible to encode each digit separately and store the number as a sequence of "text"
characters. E.g. instead of calculating the binary equivalent of the number, you could
store the it as a sequence of five characters, "1", followed by a "2", "8", "7" and "6".
This method is not quite as efficient as the first method since it requires more space.
(As an exercise, you should check how many bits or bytes would be needed to
represent 12876 using its equivalent binary number and using text representation.)
Also, computers are much better at doing number arithmetic in their native binary
number representation.
32
65
A
97 a
33 !
66
B
98 b
34 "
67
C
99 c
35 #
68
D
100 d
36 $
69
E
101 e
37 %
70
F
102 f
38 &
71
G
103 g
39 '
72
H
104 h
■ ■■
■ ■■
■ ■■
Table 2.1. Decimal equivalents of some ASCII codes
2.1.1.3 How Computers Store Sound
The same principle applies here as with storing text: we need to find some way of translating
sound into a sequence of numbers. This process is called digitisation. It has been discovered
that voices, music and any other sound signals are completely defined by the shape of their
sound waves: their frequency. (We ignore the loudness or amplitude here for simplicity.) To
make an almost perfect recording of any sound signal, all one needs to do is to check or
sample the sound signal many thousands of times a second and record the frequency of the
signal at each interval. This frequency can be represented as a number, typically below 20 000
(Hertz). One second of sound can therefore be represented as a long (say many thousands)
sequence of numbers, each number corresponding to the frequency of the sound at each
fractional part of a second (a real split-second!). If this seems like a lot of data for a short time
of music, you're right! As you may have guessed, this is the way music or sound is recorded
on compact disc, digital audio tape or sent between digital cellular telephones.
This discussion should explain why there is a trade-off between the amount of data and the
quality. You can increase the accuracy of the sound by using larger numbers to represent the
frequencies (a popular choice is between 8 or 16 bits). And you can increase the sampling rate
Discovering Information Systems
13
2. Transforming Data into Information Section I
(how many times per second the frequency gets "checked" or converted into a number, or in
how many parts you split the second). Doing so will increase the fidelity of your data i.e. the
quality of your digital recording. But: you also increase the total number of bits you require!
It should also be said that there are many alternative ways of representing sound in digital
format, often vastly more efficient but typically less universal. For instance, the different
notes of sheet music can easily be converted directly to numbers, without having to convert
them first into frequencies. This is the principle behind MIDI-based music. This method
would require less than one-thousandth of the number of bits generated by a sampling
method!
2.1.1.4 How Computers Store Graphics
How can a computer store a picture of, say a mountain? Again, we need to find a way of
converting the picture into a set of numbers. This is done in a manner very analogous to
digitising music. Basically a picture is divided into many tiny squares or dots (" raster-is ed").
If you look closely, you can still make out these dots on a television tube, newspaper
photograph print or the printout of a low-quality computer dot-matrix printer. Each dot
represents a tiny fraction of the overall picture and is therefore called a picture element or
pixel, which is then converted into a number. For a black-and-white picture this number will
indicate how light or dark the pixel is, using a grey-scale of say 0 to 100, with 0 representing
very white and 100 very black. (A real grey-scale will again use a "funny" number based on a
round power of two - usually 256, which equals 2x2x2x2x2x2x2x2 and takes exactly one
byte!) Colours can also be coded although not quite as straightforwardly. Colour coding is
based on the fact that all colours are basically a combination of three primary colours. Three
numbers representing the percentage of each primary colour to be used will uniquely reflect
any colour of the dot. As with sound, the more accurate the numbers (more bits !) for each
colour and the finer the raster grid, the higher the quality of your picture but also the more
data is required. A good quality picture could easily require many millions of numbers to
encode.
2.1.1.5 Animation and Movies
To record animation or "moving pictures", we make again use of the "time slicing" technique.
Anyone who knows some of the technicalities of film movies or television is aware that the
human eye can easily be fooled into seeing movement if shown a series of still pictures in
quick succession. A film is indeed nothing but a series of photos taken at intervals of about a
thirtieth of a second, which are shown rapidly one after the other. This is also the way cartoon
movies are made: several tens of slightly different drawings have to be made for each second
of movement. So digitising movies involves nothing but storing many, many successive
pictures, often together with one or more sound tracks! Needless to say, this involves huge
quantities of numbers.
2.1.1.6 Limits to Computer-based Data Processing
From the previous discussion, you have hopefully developed a more general idea of how data
gets stored on computers. We experience the real world as continuous: time and space can be
divided into as small a piece as we want. Digitisation involves slicing and cutting a big chunk
14 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I 2. Transforming Data into Information
of information about an object into very small elements and somehow catching the essence of
each of these elements in a number. Usually there is more than one way to do this and often
incompatible competing "standards" exist.
The question naturally arises: can all data be digitised? This is still an unresolved question.
The following are just some of the limits to our current computer technologies.
• Digitisation of sensual data such as smell or taste is currently at a very primitive stage,
although some success has already been achieved.
• Another problem area is accuracy: digitisation of real world objects is always an imperfect
approximation of reality; sometimes we encounter limits to the precision that can be
obtained. For many purposes, e.g. converting currencies or calculating taxes, this limit is
of theoretical concern only. But for other purposes, such as weather prediction, fluid
dynamics modelling etc., these are very real concerns.
Only time will tell whether these limits are only temporary shortcomings of the technology or
reflect real limits of digital information processing.
2.1.2 Measuring Data
Once you have a basic understanding of how data is stored, it is relatively straightforward to
tackle the question of how data can be measured. The simplest measure of data is its quantity
or size: how much data is there? If we take our previous sample of text: "The Bulls have won
the match!", then it is fairly easily to work out that it contains 29 characters (spaces and
punctuation included). Thus, if each character requires 8 bits (which is one byte) to encode,
then our sentence is 29 bytes long.
Just to get some feel for data quantities, some examples follow to indicate typical byte sizes.
• One page of typewritten text. A typical page contains around three thousand characters
(about 50 lines of text of 12 words of 5 letters each), so it would be about 3000 bytes. How
far is Cape Town from Simon's Town? You're likely to reply using kilometres (40) rather
than metres (40000). So whenever we refer to many thousands of bytes, we will also use
the abbreviation kilobytes (or KB for short). A typed page with text holds a couple of
kilobytes of information.
• A paperback novel. A typical novel consists of a few hundred of pages, say two hundred
and fifty. Two hundred and fifty times three kilobytes is close to one million bytes. Most
novels are between one half and two million bytes. Again, we try to avoid large numbers
and one million bytes, or one thousand kilobytes, is called a megabyte (usually abbreviated
to MB).
• Two hours (a double CD) of high-fidelity music. This calculation is a bit technical and it
is really the end-result in which we are interested. But for those of you who are interested,
here goes. Frequencies are encoded as two43yte (or 1643it) numbers and the frequency is
sampled about 40000 times each second. There are two stereo channels so for each second
Discovering Information Systems 15
2. Transforming Data into Information
Section I
of music we need 2 x 40000 x 2 = 160 000 bytes or 160 KB. Two hours of music is 2 x
3600 seconds i.e. 7200 seconds x 160 KB per second = 1152000 KB = 1152 MB. One
thousand megabytes is called a gigabyte (GB for short).
• Photographic data sent back from a space exploration vessel. On its mission, a
planetary explorer could send back to earth medium resolution colour pictures of 10
megabytes each, at a rate of about 100 per day. Each day mission control receives
therefore 100 x 10 megabytes = 1000 MB = 1 gigabyte. If the space voyage lasts three
years (a typical trip to the outer planets) we have about 1000 days' worth of data i.e. 1000
gigabytes. You've guessed it: 1000 gigabytes also has a special name, a terabyte. A full-
motion video would (uncompressed) also contain about a terabyte of (uncompressed) data!
From the above, you can see that digitising visual and audio signals requires a lot more data
than text. A picture is worth a lot more than a thousand words, in fact it is more like a million
words ! And actions speak much, much louder than words if a short movie scene requires the
equivalent of many billions of text words to store digitally.
Trivial fact: The film Toy Story took over 800 000 hours of work on 300 computers to
produce. Each minute of animation took about two days to create.
2.2 Information
When we compare data with information, the first obvious difference is that information must
be seen in a context in which it makes sense. This context usually relates to an action or a
decision to be taken. In the case of a credit manager, information about outstanding accounts
might be needed to decide whether to pursue a tighter credit policy. A telephone directory
provides useful information when you need to contact a friend Sometimes a decision might
be made that no action needs to be taken as a result of information being provided; after
checking the results for the first class test, your lecturer may decide that additional revision
exercises are not needed! To put it into other words: there must be a useful purpose before
data becomes information. In an organisation, we will try to collect only the data that satisfies
the informational needs of the system's users, since superfluous data costs time and money to
collect and store.
The second characteristic is that there must be a process by which data gets transformed into
information, as illustrated in figure 2-2. This process can be as simple as looking up and
locating a single data element in a data set (e.g. one number in a telephone directory),
counting or totalling data elements (accounts) or it can involve more advanced statistical
processing and charting.
DATA
PROCESS
INFORMATION
Figure 2-2: Transforming data into information
16
[Free reproduction for educational use granted]
© Van Belle, Eccles & Nash
Section I 2. Transforming Data into Information
2.2.1 Qualities of Information
We live in a time where we are bombarded from all sides with information: the age of
information overload. (Just ask any student!) It is becoming a vital survival skill to assess the
quality of information. What distinguishes "good" from "bad" information? The following are
just some of the characteristics or attributes of information. But note that these attributes are
not always of equal importance - depending on the particular type of decision that needs to be
made and the degree of risk attached to it, some attributes may be more critical than others.
•
Accuracy. How accurate is the information or how much error does it contain? We do
not always require perfect accuracy. Where a bank statement or invoice should be
100% accurate (although it may be rounded to the nearest cent or rand), "Errors &
Omissions" of many millions of rands in the South African export statistics could be
acceptable. If you want to drive a big lorry across a small bridge you need to know its
weight to the nearest ton whereas if you wish to purchase diamonds you want a weight
measurement which is significantly more accurate! If I, as production manager of a
sweet factory, need to know how much stock of sugar we have available for the
production of a particular sweet, I may not be satisfied with the answer "a lot" or
"plenty".
Reliability. How dependable is the information? This is closely related to but not the
same as accuracy. It is related to how the information was obtained, e.g. the quality of
the source of the information. Take the example of the sweet factory. I ask the
inventory manager how many tons of white sugar are remaining. She informs me
"36200 kilograms" but obtained this figure by looking at the size of the pile of sugar
and making a rough estimate or, even worse, checked the brown sugar instead.
Despite the apparent accuracy, 36200 kg is not a very reliable figure.
Completeness. Does it contain all the important facts? In the above sugar example,
she could give the exact weight but fail to communicate that she is expecting another
200 tons of sugar to arrive later that day, or that they are about to use most of the
sugar for the production of another type of sweet.
Verifiability. Can the correctness of the information be checked? Is it possible to
obtain another estimate for instance by using another source or another method? In the
sweet factory, one might be able to use a computer-based inventory system to verify
the answer given by the manager. On the other hand, if large quantities of sugar move
in and out the warehouse all the time, it may be impossible to verify the figure.
Relevance. How pertinent is the information to the question or decision? The course
fees, the academic standard (pass rates!) and job opportunities are all factors which
may have led you to choose to study Information Systems at UCT but some would
have been more relevant than others. The Rand/Dollar exchange rate is more relevant
to South African exporters than it is to Brazilian farmers.
Timeliness. How up-to-date is the information? There is little use in having a
computer program predict the next day's weather with perfect accuracy if it takes 48
hours to produce the forecast!
Discovering Information Systems 17
2. Transforming Data into Information Section I
• Simplicity. How complex or detailed is the information? To indicate the outstanding
performance of students on the IS 1 course, I could give standard deviations and other
probability distribution characteristics of student marks over the last 10 years, full
result lists or simply the pass rate of last year's students. A mere pass rate would
probably be too simplistic while a complete list of results is too detailed. Best would
be to give a bar chart showing the distribution of symbols.
• Cost. How much did it cost to produce the information? One should always compare
the cost of producing the information with the value gained from it. There is no need
to write a five-page report with many tables and charts to answer a simple question or
indicate that performance is in line with expectations or budget.
2.2.2 Measuring Information
As you have already seen, it is not difficult to measure the size or quantity of data. The
measurement of information is more complex. Consider the two statements "Bulls win" and
"The Bulls team has shown its superiority by winning the match"; their information content is
very similar, yet the second sentence contains almost eight times as much data as the first.
Also, the amount of data in a message may change depending on the method used to encode
it. A sentence coded in Morse code has about only about a quarter of the data of the same
sentence in Unicode. But Unicode can also cope with Vietnamese text whereas Morse code
cannot even distinguish between capitals and lower case Roman alphabet.
This has prompted communication theorists to look at another way of measuring information,
which involves reducing it to the smallest expression that can still communicate the required
content. For instance, the Bulls can either win or not, so the shortest way to send a message
expressing the result of the match would be through a (previously agreed upon) binary code
e.g. 1 = Win, 0 = No win. So the information content of "The Bulls have won the match!" can
be reduced to one single bit.
Of course, we might require more detailed information about the result of the match,
especially about the "no win" option. A perhaps more appropriate coding scheme would be
0= Bulls lose; 1= draw; 2= Bulls win; 3= match has been postponed. In this case we would
have an information content of two bits. See whether you can work out a scheme for coding
these four options using only two bits (i.e. in binary format).
An alternative concept for measuring information is based on its "surprise value", which
calculates the number of options you have before you receive the information and measures
how the information reduces these possibilities. Information reduces uncertainty. Drawing a
playing card at random from a full deck has 52 possibilities, so the surprise value or
information content of which card has been drawn is 1 in 52 or (slightly less than) 6 bits since
6 bits can encode 64 different options.
2.3 Knowledge and Wisdom
The concepts of data and information, which have been discussed in some detail, are actually
the two lowest levels of a hierarchy (see Figure 2-3).
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Section I 2. Transforming Data into Information
Knowledge is a much broader concept than information because knowledge consists of many
pieces of related information, and has a structure or organisation whereby each piece of
information is linked to others. In addition to a large number of data facts, knowledge often
includes rules to validate new information, algorithms by which to obtain or derive
information, frameworks that indicate what types of information are relevant in which
context, information about the information and its structure (meta-information) etc. If
information is data in the context of a question, then knowledge is what enables you to ask the
right questions. Knowledge consists of knowing which action alternatives are available and
what information is required before one can decide on a specific course of action.
A related concept is expertise, which consists of more detailed and validated (proven)
knowledge in a selected area e.g. a car mechanic is supposed to have a lot of specific
knowledge about the functioning of a motor car and its engine. Expertise has the connotation
of being specific to a more restricted (often quite technical) domain, but also deeper or more
detailed than knowledge.
Figure 2-3: The hierarchy from data to wisdom
Finally, wisdom adds yet another dimension by combining knowledge with experience,
critical reflection and judgement, such as when assessing the moral and ethical implications of
a decision. The issue of representing higher levels of information e.g. knowledge, reasoning,
expertise, experience, etc. is also still very much the subject of current research. No computer
has (yet?) been able to generate original wisdom. But then, so have few humans !
2.4 Producing Business Information
The various characteristics of data and information that have been presented in this chapter,
are directly relevant when developing systems that are intended to produce business
information. In deciding what information is needed, it is important to consider how it will
help to reduce uncertainty (surprise value) and how concisely it can be communicated (size).
Not all of the attributes of information are equally important in every situation: in one case,
early access to information may be more valuable than extreme accuracy, while in another
case accuracy may be sufficiently vital to justify a time delay. If you are choosing a movie to
watch this evening, you do not need to know all the details of the plot; if you are thinking of
investing in a film production, a lot more information will be needed, even if it takes longer to
acquire. A knowledgeable business manager will ensure that appropriate information is being
provided to meet specific business requirements.
Discovering Information Systems 19
2. Transforming Data into Information Section I
Careful analysis is needed to identify the data that will be used to produce this information.
How well can its truth value be established? If you are not sure whether your facts are correct,
then any business decision based on those facts is likely to be of dubious value - illustrated by
the acronym GIGO (garbage in, garbage out). Sensible decisions need to be made about the
types of data that will be stored, and the size implications: consider the difference between
storing the sound of a spoken message, or its text equivalent.
Finally, all levels of the organisational structure must be catered for. Data accumulated
through the TPS must be sufficient to generate the various types of MIS reports, to allow for
forecasting using the DSS, and to explain trends over time which could influence strategic
planning. As we commented earlier, there is more to an information system than simply
buying a computer !
2.5 South African Perspective
The rapid growth of Nando' s fast-food franchise created a need to manage its operations more
effectively, particularly because until recently information from separate stores was only
supplied to strategic management on a monthly basis. Information technology has now been
used to collect operational data which provides managers with instant access to information
about sales (at daily or even hourly level), profit margins, turnover, service problems and
sales trends. Ten strategic Key Performance Indicators were identified that allow strategic
management to monitor problem areas at individual store level and improve customer service
while minimising operational costs. Errol Epstein, the MIS director at Nando' s, comments
that as a result of their new information system "we have an holistic view of our business and
can manage our stores efficiently, cut down on wastage, and build our brand strategically".
2.6 Beyond the Basics
Knowledge is more complex than either data or information, and is more difficult to define
and to store. Knowledge management systems attempt to capture organisational knowledge,
including undocumented personal knowledge based on experience, so that it can be shared
and applied effectively throughout the organisation. This requires the identification of
valuable knowledge and where it is located, the extraction and encoding of the knowledge,
storage, maintenance and retrieval processes for the knowledge base, and delivery of
knowledge to recipients when needed. For example, BP has captured knowledge related to
drilling malfunctions based on the practical experience of its technicians around the world,
which can be used to provide solutions for problems that may occur in the future.
Grant Brewer of Ernst & Young believes that knowledge sharing should be a part of every
organisation's information strategy (Intelligence magazine, November 2002). "Your
information strategy should be to ensure that employees have ready access to current
information. You then have to tackle the more difficult task of getting your employees to
share their expertise, which most often comes in the form of experience rather than structured
learning. The intellectual capital of your employees is possibly the most valuable asset in your
organisation."
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Section I 2. Transforming Data into Information
2.7 Exercises
2.7.1 Data encoding
A simple way to make a code is to think of a word or phrase and write it down, followed
by the rest of the letters of the alphabet that you didn't use in the phrase, and then replace
the original letters of your message with the code letters in corresponding positions. The
reason you use a specific word or a phrase before the other letters is because that makes it
easy for you and your correspondent to remember the key without having to write the
code down, and risk having it discovered by the enemy. (If a letter is used more than once
in your word or phrase, just leave it out after the first time you use it.)
• Try using your first name as the key for encoding the message "Data must be decoded
to be understood".
2.7.2 Binary numbers
• What is the decimal equivalent of each of the following? 1001 1 , 01 1 10, 10101
• Write each of the following numbers in binary format: 13, 22, 9
2.7.3 Data vs Information
At the end of the year, assuming that your student fees have been paid, your exam results
will be posted to your home address. The statement you receive will show your name and
student number, your degree, and your final result for each course. It will also inform you
whether you have been awarded any supplementary or deferred exams, and whether you
have met the readmission requirements for your degree.
• In order to generate this document, what data would have been captured and when?
• What processing of the original raw data would have taken place?
2.7.4 Information attributes
Refer back to question 1.6.2 at the end of the previous chapter, in which you identified
organisations that have recorded your personal details. How accurate is that data at the
present date (i.e. have you changed address, phone number etc)? In what ways might
incorrect data affect the usefulness of reports or cause inefficiency of business processes?
Discovering Information Systems 21
3. How Systems Function Section I
3. How Systems Function
An information system is, as its name implies, a special type of system. In this chapter we will
introduce you to the basic systems concepts, and briefly explore some of the systems theories
that are directly applicable to organisations. Along the way, we hope that you will master the
practice of looking at your environment through "systems-coloured glasses" and applying
these new principles to the world around you.
3. 1 What is a System ?
As a university student, you form part of the educational system, regardless of what subjects
you are studying or how well you perform. Your body in turn is a highly complex
biochemical system, as is the annoying mosquito buzzing around in your room or the more
restful plant standing next to your window. You, as an individual, also form part of your
family (social) system. The electrical light illuminating your room forms part of the electrical
(energy) system, which, like the plumbing or air-conditioning system, is part of your house or
hostel, which can also be seen as a (physical) system. The pen you are holding in your hand is
a small, self-contained system, as is the whole earth ("Gaia"), which is in turn a sub-system
of our solar system. Once you start looking for systems, they seem to crop up everywhere.
But what, exactly, is a system? What have all of the above systems, despite their apparent
diversity, in common?
3.1.1 Definition of a System
Since a system is a subjective concept, there is no unanimously accepted definition of a
system. In order to study this phenomenon more closely, we will adopt the following
definition:
• A system is an organised assembly of components with special relationships between
the components.
• The system does something, i.e. it exhibits a type of behaviour unique to the system
or has a specific objective or purpose.
• Each component contributes specifically towards the behaviour of the system and is
affected by being in the system. If a component is removed, it will change the system
behaviour.
• Someone has identified the system as being of special interest.
Not just any random collection of parts or elements constitutes a system For example, a pile
of rocks is not a system, just like a random collection of words does not make up a
meaningful sentence. There needs to be a definite (perceived) structure that has some form of
order, pattern and purpose. Sometimes the structure may be very tenuous, apparent only to
few observers. At other times observers may agree on the fact that a given structure
constitutes a system but there may be disagreement about what exactly is part of the system
and what not i.e. its exact boundaries. An information system is a system that gathers and
transforms data in order to produce information for its end-users. If it is to function
successfully, then its developers and its users must agree on the purpose of the system, its
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Section I 3. How Systems Function
components and the relationships between them.
Another essential element of the definition involves the subjective aspect: a system is not an
objective "thing" out there that exists on its own but it is something attributed to a set of
interrelated components by an observer.
3.1.2 The Systems View and Systems Thinking
The definition of a system is, however, somewhat of an academic exercise. The real essence
of systems theory is being able to look at the world from a different perspective. The systems
view involves adopting the reference framework and the terminology of systems theory,
trying to apply various analogies with other systems and checking which of the systems laws
and theories hold for the system of interest. Systems thinking is just a whole new way of
thinking about the world in which you live. Being able to adopt this approach is quite an eye-
opener for many, a pleasant and novel experience in fact, and much more important than
merely being able to explain all the various concepts that will be introduced in this chapter.
Why is this systems view so important? Can we not just learn about the technology of
information systems and dispense with more philosophical matters? The problem with the
purely technical approach is that it often fails to take into account the inter-relation of
problems and proposed solutions, which is incorporated in the systems view. The study of
information systems is about solving an organisation's problems with respect to its
information needs. Installing a computer is often a quick fix but may turn out to be a very
sub-optimal solution, not taking into account many of the human and organisational factors.
Some authors go even further and claim that most of today's complex problems, such as
crime, drugs, poverty, war, suicides, breakdown of family structures, unbridled materialism,
global warming and more, are a result of the short term and technicist vision of society's
decision makers who fail to adopt a holistic systems view when addressing problems.
3.2 Elements of a System
3.2.1 Environment and Boundary
As soon as we identify a system, we define a boundary: what is inside the boundary belongs
to the system, everything outside the boundary is not part of the system However, most
systems do not exist in isolation. Systems, or their components, inter-act with the world
outside their boundary. The part of the outside world with which the system interacts is called
the system's environment. What about the boundary itself: do you think that it belongs to the
system itself, or is it part of the environment?
3.2.2 Inputs, Transformation Process and Outputs
The interactions of a system with its environment can take the form of inputs or outputs.
Inputs take the form of material objects, energy and/or information flowing from the
environment into the system. Outputs are released or sent from the system back into its
environment. This output can either be useful (to some outside system) or waste. Within the
system, the inputs usually undergo some kind of transformation process so that the outputs
are different from the inputs. Often, inputs and outputs undergo further specific
Discovering Information Systems 23
3. How Systems Function
Section I
transformations at the system boundary; the system components responsible for these
transformations are called the interfaces.
SYSTEM ENVIRONMENT
INPUTS
r ~\
TRANSFORMATION
PROCESS
V J
OUTPUTS
SYSTEM BOUNDARY
Figure 3-1: The basic elements of a system
Some systems perform very simple energy or matter transformations. Other, more complex
systems, such as our human mind, perform quite intricate and sometimes even
incomprehensible transformation processes (as evidenced by some student examination
answers!) A motor car, for instance, turns petrol and oxygen into motion, heat and a variety of
waste gases (exhaust fumes). It also takes its occupants from one physical location to a
hopefully different location.
Information systemsError! Bookmark not defined, accept data as input, via an interface such
as a computer keyboard or barcode scanner. Transformations may be trivial (counting or
adding a set of numbers, copying a set of data), slightly more complex (e.g. drawing a map
from co-ordinate data) or extremely complex (making a medical diagnosis based on
symptoms and signs, deciding whether to launch a new product range, translating a poem).
The information outputs of the system will finally be presented to end users, via an interface
such as a computer screen or a printer.
3.2.3 Components and Subsystems
A system consists of various components which, taken together, make up the system. The
interaction between the system components is responsible for processing the inputs into
outputs. Although components can also interact directly with elements from the environment
i.e. across the system boundary, most of their interactions will be with other components
within the same system.
Often, components themselves can be viewed as smaller systems on their own: they are sub-
systems of the system under consideration. The motor car mentioned above, for instance, has
an electrical sub-system and an air-conditioning sub-system.
In the case of an information system, the basic components that interact are
• the hardware or physical equipment used to process and store data
• the software and procedures used to transform and extract information
24
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© Van Belle, Eccles & Nash
Section I 3. How Systems Function
• the data that represents the activities of the business
• the network that permits the sharing of resources between computers
• the people who develop, maintain and use the system.
Each of these components will be discussed in more detail in later sections of this book. At
the same time, don't lose sight of the fact that the information system in turn is merely one
component of the organisation, and must interact with other departments and business
activities.
To understand the workings of a system, it is often useful not to take into account all the
details of each of the subsystems. The level of detail with which you study a given system is
called the granularity. If you want only to drive a car, you may be satisfied with a fairly
coarse granularity i.e. you need to know about such things like the ignition and petrol tank but
not about the condenser or the differential. However, if you are a car fanatic or repair
mechanic (or if the car does not want to start), you need a much more detailed understanding
of the subsystems within the car i.e. you need to study the system at a much finer granularity.
The coarsest possible description of a system is called the black box view of the system: you
just describe the inputs and outputs but make no attempt at understanding what actually goes
on inside the system. When first analysing or discussing a system, it often makes sense to
view its subsystems as black boxes. The telephone communication system is, for most of us,
very much like a black box: we dial a number and, if all is well, we hear a familiar voice in
our handset. Luckily, we do not need to know how the various telephonic exchanges managed
to establish our connection or how our voice signal got transmitted. Our scientific pocket
calculator is another example: when we want to calculate the cosine of a certain angle, we
enter a number, press on the cosine function and it displays a result without us being aware of
how in fact it arrived at this result. If a black box hides all internal system details, what do
you think is meant by a white box? A grey box?
Trivial fact: The biggest machine in the world is the telephone system. The vast network of
cables and satellites links together over a billion different telephones, fax machines and
modems that connect a third of our world.
3.2.4 Objectives, Control and Feedback Loops
Systems have a function, goal or purpose. This goal can be internalised e.g. the desired room
temperature for a central heating thermostat device or the profit motive in a commercial
business enterprise. This purpose can also be imposed from the outside e.g. when we use a
motor car to drive from our home to the shop. In order for the system to achieve its goal(s), it
needs to be able to modify its behaviour. Control is the mechanism whereby special control
signals or, when coming from outside the system, control inputs, modify the processes and
activities which occur within the system
The controller is the component or (sub-)system which exercises the control and can be part
of or outside the system under consideration. The controller observes the behaviour of the
system, typically by looking at certain system outputs and compares them to the desired state
Discovering Information Systems 25
3. How Systems Function Section I
or objective. In the case of a deviation, the controller would adjust certain (input) controls to
modify the system's processes. This 'round trip' of using output signals and using them to
modify input signals is called a feedback loop, and the whole process is one of feedback
control. There is always a slight delay before the output can be "interpreted", the consequent
control changes are effected and the system behaviour is adjusted. This delay is called the
(time) lag. Lags can vary from the milliseconds it takes an ABS car braking system to release
the brakes of a locked wheel to the many years it may take to vote an unpopular government
out of office in a country's democratic political governance system. In the case of a business,
output from the MIS will be used to provide feedback regarding routine business transactions,
so that managers can monitor operational activities and introduce changes if necessary.
System feedback can be positive or negative. If the system behaviour needs to be altered
(reversed) in order for its output to move closer to the desired state, then we have a negative
feedback loop. Two examples are the way a singer adjusts the tone of her voice so that it is in
harmony with the orchestral instruments or the correction that we apply to the steering wheel
if the car moves slightly out of its lane. However, if the feedback loop reinforces the current
behaviour of the system, then we speak of positive feedback, such as when a student achieves
good marks after studying hard for a test. Consider a small boy throwing a tantrum: his
mother could discipline him by sending him to his bedroom, or could pacify him by giving
him a sweet. Which of these would be positive and negative feedback, and why?
The study of how systems can be controlled, with a particular focus on automatic or self-
controlling systems, is called cybernetics. Although it initially arose from engineering, it is
now considered to be a sub-discipline of general systems theory.
3.3 Systems Concepts
When analysing systems and their interaction with the environment, a number of useful
concepts should be borne in mind.
3.3.1 Open vs Closed Systems
Any system that interacts with its environment is called an open system. There is in reality no
such thing as a closed system, which would have no inputs or outputs and therefore, in a
sense, no environment. Nevertheless, some systems are mainly self-sufficient whilst other,
more open systems have a much greater degree of interaction with their environment. It is
important to cater for this interaction with the environment when planning any system - there
would be no point in starting a business that manufactures top quality goods, if you have no
way of delivering them to your potential customers, or if you do not have access to the raw
materials that you need!
3.3.2 Dynamic vs Static Systems
A dynamic system is a system that has at least one (and usually many) activity or process; as
opposed to a static system, which has no activity, whatsoever. Again, there are very few
completely static systems and we typically use these concepts in a relative sense: we refer to
one system as being more dynamic than another, more static system. The more dynamic a
system, the more flexibility must be built into the inter-relationship of components, allowing
26 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I 3. How Systems Function
them to function in different ways as activities change - especially important in a modern
business environment.
3.3.3 Continuous vs Discrete Systems
A continuous system is a system where inputs (and outputs) can be varied by extremely
small amounts or quantities. Discrete systems are systems where the inputs or outputs can
take on only certain discrete or distinct values. A traffic light (robot) is a discrete traffic
signalling system because its three lights (green, amber or red) are either on or off. It remains
discrete, even if we extend the number of signals e.g. some lights can be switched on
simultaneously (as in England where a simultaneous amber and red light indicate an imminent
change to green) or allow for flashing lights (to indicate malfunction or during night-time
operation). A mercury-based thermometer, like many physical systems, is a continuous
system as the level of mercury rises or falls gradually along with imperceptible fluctuations in
the environment's temperature. Many electronic systems are a combination of both e.g. a
digital thermometer has a sensor that records temperature as a continuous input but displays a
temperature reading which has been rounded to the nearest degree.
Discrete systems have clearly identifiable states. The traffic light is either green or not when
you cross the intersection; there is little use in arguing with the traffic officer that it was still a
little bit green! A continuous input or output is often converted or approximated to a nearly
continuous but actually discrete measure, such as when we measure a temperature to the
nearest tenth of a degree or time the finish of an athlete to the nearest hundredth of a second.
This enables us to model the real, physical world with electronic equipment such as
computers, which can work only with finite precision (i.e. discrete) numbers. A good example
of how well this conversion process can work is the Compact Audio Disc recording system
which samples the music many thousands of times a second and converts the frequency of the
sound signal at each time point into an integer number between 1 and 60000.
3.3.4 Structure and Hierarchy
The interactions between the various sub-systems and components of a system display some
pattern or regularity. In this sense the observer can identify certain relationships, which
contribute to the overall behaviour of the system. The entire set of relationships is referred to
as the structure of the system. In a purely physical system, the physical location of the
components and the connections between them will account for most of the structure e.g. the
way the various parts of a car are joined together would account for its structure. In systems
that involve informational and conceptual components, the structure will be much less
tangible and involve some level of abstraction e.g. when you try to identify the social
structure of an extended family unit.
Often, components of a system can be regarded as smaller systems in their own right. These
are called sub-systems of the system under consideration and the latter probably constitutes
most of their environment. These smaller sub-systems are thus embedded within the system,
which in turn may be a sub-system of yet another, larger system: the supra-system. This
nesting of systems within systems within systems is referred to as a system hierarchy. A
common example is the physical universe (the ultimate physical supra-system), which is
Discovering Information Systems 27
3. How Systems Function Section I
made up of galaxies (our Milky Way is one), which in turn consist of solar systems (e.g. ours
with the familiar sun at the centre), which contain planets (including the planet Earth with its
moon). Our planet Earth consists of a biosphere which contains all living things, including
human society, which is in turn made up of social sub-systems or cultures, made up of
humans (biological systems), made up of cells, in turn consisting of complex molecules etc.
all the way down to the basic building blocks of matter (currently quarks). Another example is
a large multinational organisation (one system, whose super-system is the international
political economy) which may consist of various national companies, who in turn have
regional branches or establishments, which may consist of various departments or project
groups etc.
3.3.5 Holism and Emergent Properties
The chemical behaviour of one molecule of water (H20) is very different from the behaviour
of large amounts of them when they make up an ocean. The inorganic chemist will have little
to share with the wave surfer, art photographer or scuba diver about the properties of water.
We are also familiar with the fact that the actions of a large mob or crowd may be very
different from the behaviour of any individuals making up the mob. And of course the
psychological and emotional behaviour of an individual can not be understood from the
perspective of (or reduced to) his biological make-up i.e. his cell structure.
The perspective from which claims that many aspects of a system can be understood only in
terms of its entirety, and not necessarily be reduced to the characteristics of its components, is
called holism (the opposite of reductionism). This is often expressed in the popular saying
that a system is more than the sum of its parts. Holism also implies that it is important to be
aware of the inter-relation between the various components of a system: everything is related
to everything. When a person is ill, traditional medicine will look at the symptoms of the
patient, diagnose the illness and prescribe some medication which will cure the patient by
relying on some type of biochemical reaction within the body of the patient. The holistic
approach will look at the lifestyle of the person, her emotional well-being and any
psychological factors which may have contributed to the illness, i.e. a much wider perspective
is taken, and illnesses are viewed in the context of the individual as a social, psychological
and biological system.
The holistic systems view implies that a system has certain properties, qualities or attributes
which cannot be reduced to or understood from its components alone. These properties are
called the emergent properties of a system. Examples of emergent properties are the
corporate culture of an organisation, the consciousness of a living individual, the feel of a car,
the atmosphere or vibe of a pub, the cultural identity of a social group.
3.3.6 Entropy
An important measure of a system is the amount of order (in the case of matter or
information) or potential energy it contains. The measure for disorder or energy degradation is
entropy: the higher the level of disorder, the higher the entropy level. All systems change
over time and, unless a system can draw on resources from the environment, it will tend to
become more disorderly or lose energy ("run down") i.e. entropy increases. This is one of the
28 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I 3. How Systems Function
systems fundamental laws; it is a generalisation of the second law of thermodynamics, which
states that the energy in the universe degrades irreversibly as time passes.
The concept of entropy is a fairly difficult one to understand conceptually. Though it is
possible to define it more rigorously (i.e. mathematically!) the following examples illustrate
the essence of the concept. A hot plate of food or an ice-cold drink placed on the table will
tend to take on the ambient room temperature. A spring-driven clock or watch will slowly
unwind and stop. A house or garden that is not maintained will slowly become more and more
disorderly. Music or video signals on a magnetic tape will slowly fade away until, after many
decades, nothing but noise remains. As a log fire keeps radiating heat and light energy, it
slowly cools down until nothing but ashes remain. In every one of these examples, the input
of energy serves to restore the system temporarily to a lower level of entropy (although this
usually implies an increase in the overall entropy of the supra-system).
3.4 South African Perspective
Careful analysis of an intended system (its inputs, outputs, interfaces, processes etc) can prove
invaluable in identifying unforeseen problems at the planning stages. Apparently this did not
happen in the case of the renovation and expansion of the facilities served by the upper cable
station on Table Mountain - no process was included to dispose of the increased volume of
sewage that resulted, until a major problem had become apparent!
Until the end of 2001, a mixture of partially treated sewage from lavatories and waste water
from the restaurant's sinks and dishwashers was allowed to seep down the mountain, killing
vegetation and causing an outcry among environmentalists. Since then, effluent has been
stored in a tank on the summit and is removed by cable car, but with the expansion of
facilities and increasing numbers of visitors, the cableway company is concerned that this is
not a sustainable solution.
3.5 Beyond the Basics
A number of system rules, which have been developed based on general systems theory, are
particularly relevant to business. Examples of these are:
• Law of requisite variety: Control can be obtained only if the variety of the controller is
at least as great as the variety of the situation to be controlled. In other words, every
possible situation should provide feedback, which can be acted upon if required; this
can be applied to controllers ranging from smoke detectors to computer error
messages.
• Law of requisite hierarchy: The weaker and more uncertain the regulatory capability,
the more hierarchy is needed in the organisation of regulation and control to get the
same result - where systems (or people) are not self-regulating, then strong
management supervision becomes essential.
• Sub-optimisation: If each subsystem, regarded separately, is made to operate with
maximum efficiency, the system as a whole will not operate with utmost efficiency. In
practice, the goal of the entire organisation must be the first priority, even if this is
achieved at the expense of some projects or departments.
Discovering Information Systems 29
3. How Systems Function Section I
• 80/20 principle: In any large, complex system, eighty per cent of the output will be
produced by only twenty per cent of the system. This applies to people, equipment,
products, etc, and it is worth trying to identify the most productive 20% to make sure
that it continues to function effectively.
• Redundancy of resources principle: Maintenance of stability under conditions of
disturbance requires redundancy of critical resources. So make sure that you have
spare parts for critical equipment, and staff who are able to fill in if a key employee is
off sick!
• The environment-modification principle: To survive, systems have to choose between
two main strategies. One is to adapt to the environment, the other is to change it. And
after all, changing the (customer) environment is what marketing is all about.
3.6 Exercises
3.6.1 Systems concepts
Consider the following two systems:
1 . McDonalds hamburger franchise in Rondebosch
2. A large hospital, e.g. Groote Schuur
• Give examples for each system of the system goal or purpose, 2 inputs, 2 components,
2 processes, 2 outputs, one sub-system, one supra-system and an external feedback
mechanism.
• How would you measure whether the entropy of each system increases or decreases?
3.6.2 Systems Thinking
"Systems thinking" refers to trying to solve problems by looking at their wider context,
and examining the root causes, interactions, feedback mechanisms, etc.
• Think of an example of a problem that cannot be solved effectively by addressing
only its apparent symptoms, and explain why this is the case.
3.6.3 The Systems View
Make a list of at least 10 different systems that you are a part of in everyday life.
30 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section I Case Study
CASE STUDY: GREENFINGERS GARDEN SERVICES
Greenfingers Garden Services was established in Cape Town in 1990, starting as a small
suburban garden maintenance service (mowing lawns, weeding flowerbeds, etc), employed by
a limited number of clients on an annual contract basis. Over the last decade the business has
expanded considerably, and it now has three branches (in the Southern Suburbs, Northern
Suburbs, and Camps Bay area) which offer consulting and landscaping services, one-off
"spring cleans" as well as regular garden maintenance. The company has both residential and
corporate clients, and ascribes its success to the efficient and personal service that it has
always provided.
The main Southern Suburbs branch is run by the owner, Alice Cooper, and is responsible for
overall management of the business, including all the accounting and general administration
functions, marketing, consulting, and stock. Each branch manages its own supplies of
gardening equipment and schedules its labour force (permanent and casual staff) to ensure
that jobs are completed on time.
In more detail, the business operates as follows:
• The marketing function, headed by Steve Carlton, includes newspaper, yellow pages
and radio advertising, colour brochures which can be left with prospective clients, and
regular phone calls to existing clients to check that they are happy with the service
they have received. Garden service foremen are also supposed to suggest additional
services to clients, such as pruning, replanting or fertilizing, but in many cases the
householder is not home at the time of the garden service. Steve relies on information
received from the various branches to let him know when they have spare capacity, in
which case flyers are distributed in letter boxes within a restricted area, offering
special deals on garden cleanups or new contracts for a limited time. Steve deals with
all responses and queries, provides quotations, draws up contracts, and then passes on
new client information to the accounts department.
• The accounts department receives new client information from Steve Carlton, and
receives a daily listing from each branch of jobs completed for invoicing. In addition,
they order equipment and supplies for all branches, schedule vehicle maintenance,
attend to creditor payments and client receipts, and maintain the payroll for permanent
and casual staff.
• Alice Cooper oversees the business administration herself, and does her best to keep
costs down by having equipment repaired rather than replaced, and by ensuring that
the permanent staff is kept as small as possible by utilising casual labour. However,
this increases the complexity of management, since she needs to know a week ahead
of time how many casuals will be required, so as to ensure that she will not be short-
staffed. Also, while equipment is being repaired, it is often necessary to reschedule
jobs or try to shift lawnmowers etc between branches, involving a number of
telephone calls.
• The garden equipment itself (mowers, trimmers, sprayers, clippers, spades & forks,
etc) is kept in store at each branch, and issued to each team at the start of the day. At
Discovering Information Systems 3 1
Case Study Section I
the end of the day it is checked back in, and any problems or breakages are reported to
central administration at the main branch. Central admin checks whether or not the
item is still under guarantee, and arranges for any necessary repairs to be undertaken.
Each branch also has a number of light delivery vehicles for transporting work teams
and equipment to the clients' premises.
• Greenfingers does not directly employ any landscaping consultants, but maintains a
short list of landscapers and other garden specialists who can be called on when
required. When a landscaping job is undertaken, the consultant is paid a commission
based on the value of the job, but Greenfingers make use of their own labour and
source the plants themselves. They have arrangements with a wholesale nursery for
the provision of shrubs etc at a discount price. Heavy machinery for earthmoving or
tree removal is hired when needed.
• The actual work teams who carry out the garden maintenance jobs, are managed by
their specific branches. Based on the orders received via marketing, and the regular
scheduled contract jobs, the admin department informs each branch on Mondays of
their jobs for the following week. The branch manager must then check that labour
and equipment will be available, and inform central admin of any potential problems
so that they can be resolved in good time. Each work team has a foreman and at least
one gardener who are on the permanent staff, and additional casual workers are hired
by the day. Once the work teams have left for the client properties each morning, the
branch manager compiles a list of the previous day's completed jobs, the staff
employed, and any damaged equipment, for submission to central admin.
With the growth of the business, its administration is turning into a nightmare, and Alice finds
that her evenings and weekends are being spent collating information, working out schedules,
and trying to overcome problems by sharing equipment and even staff between branches.
More and more clients are complaining that special instructions given to Steve Carlton are not
being carried out by their work team, or that discounts that were promised have been omitted
from the invoice. Alice is also aware that opportunities are being missed for the provision of
extra services such as spraying and pruning, which are highly profitable since the work team
is already on site and no additional time or cost is needed for transport.
(a) Construct a labelled diagram that will show the flow of information between central
administration, marketing, accounts, each of the branches, the work teams, and the
consultants.
(b) Explain how the automation of this information flow could improve the running of
Greenfingers Garden Services.
(c) At a Transaction Processing level, what data would need to be captured in order to
provide the input for an automated information system?
(d) Provide a comprehensive list of useful reports that could be produced by a Management
Information System, and specify who each would be used by.
(e) What feedback mechanisms could be put in place to monitor and control business
activities?
32 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II IS Technologies
Section II: IS Technologies
An information system is a system that gathers and transforms data in order to produce
information for its end-users. Typical technologies that are incorporated in this process are
hardware, software, data and networks. (The fifth important component of an information
system, people, is not classified as a technology!)
These same components are found in small, informal information systems such as the one you
use to keep track of the contact details of your friends and family. You may have phone
numbers stored in an address book, on your cell phone, and on the cover of your exam pad
(hardware); you have particular rules about whose numbers you are going to keep and how
you store them (software); the collection of numbers that you already have forms your
database; and when you update a number in your address book from the back of the exam
pad, you are transferring data between resources. But for the purposes of this book, we will
focus on the components of larger, computerised information systems, operating within the
environment of a commercial organisation.
Hardware
The most easily visible component of an information system is the hardware. One can
typically distinguish between the media used to store the information and the capital
equipment used to read, write and store the media. In manual information systems, paper is
perhaps the major information medium, although microfilm, microfiche and audio/video tape
are also still popular. Some of the capital equipment associated with manual systems are pens,
typewriters, photocopiers, filing cabinets and shelves, binders, staplers, shredders, microfilm
readers, recorders. Many of these manual technologies are still a significant component of
computerised information systems but the latter also use various optical and magnetic disc
media which can be read using only sophisticated computer input and output devices such as
scanners, printers, monitors and projectors. Other hardware includes the computer itself,
storage devices such as hard drives and a whole "alphabet zoo" of network or communication
devices and cabling.
Software and Procedures
Software consists of the methods used to record, transform and extract information. The term
is used mainly in the context of computer-based systems where it refers to the computer
programs containing detailed instructions that govern their data processing. Although
computer hardware used to receive most attention in the past, software has since become far
more important than hardware, both in terms of monetary investment and management
attention.
Generally considered part of the information systems software are the documentation,
instructions and training that are needed to use the software.
The various organisational procedures for humans also form part of an information system' s
software, though this is extending the concept of software to the realm of people, not just
computers. This would include the paper forms, procedures and guidelines for handling in-
Discovering Information Systems 33
IS Technologies Section II
coming telephone calls, dealing with mail, processing orders and purchases, internal
communication, meetings, decision criteria etc. For conceptual purposes, it should make no
difference whether a certain procedure is executed by people or by computers.
Data
Although a computer stores program software and data in the same way, from a system's
viewpoint data is a very important and separate subsystem. Only recently have organisations
(and individuals) started to realise that their databases represent huge investments, which
potentially contain significant value.
Corporate data should have its own guardians such as database administrators who control
access, integrity, format and security. Careful analysis of organisational data requirements is
needed to be able to produce useful management information to support both current and
future decision-making. In addition, the data storage mechanisms that are implemented are
likely to influence the ease with which current and historical data can be retrieved and
processed.
Networks
The networking and communications infrastructure has recently been considered to be a
separate component of information systems, although in some cases this distinction can be
regarded as a matter of personal opinion. There are definitely a number of specific decision
and management issues associated with the network infrastructure. On the other hand, the
network infrastructure also consists of hardware and software components, most of which
share attributes with the mainstream information systems hardware and software mentioned
above.
Organisations have realised that stand-alone computers present many problems:
fragmentation of data, lack of control, insufficient integration and limited opportunity for
teamwork. One of the major trends over the last decade was the move not only to have a
personal computer on the desk of virtually every knowledge worker, but to have that
computer linked to the other computers in the organisation.
Although these different technologies will be described separately in the chapters that follow,
it is important to remember that they all need to work together in order to achieve the goals of
any particular organisation. Compatibility of the various system components is vital, since the
outputs of one technology may well provide the inputs for another. And above all, the purpose
of an information system is to provide useful information to people (the non-technical
component of the system), so the selection of technologies to be used should be based on the
need to meet human requirements.
34 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 4. Hardware
4. Hardware
Hardware is the most visible part of any information system: the equipment such as
computers, scanners and printers that is used to capture data, transform it and present it to the
user as output. Although we will focus mainly on the personal computer (PC) and the
peripheral devices that are commonly used with it, the same principles apply to the complete
range of computers:
• Supercomputers, a term used to denote the fastest computing engines available at any
given time, which are used for running exceptionally demanding scientific
applications.
• Mainframe computers, which provide high-capacity processing and data storage
facilities to hundreds or even thousands of users operating from (dumb) terminals.
• Servers, which have large data storage capacities enabling users to share files and
application software, although processing will typically occur on the user's own
machine.
• Workstations, which provide high-level performance for individual users in
computationally intensive fields such as engineering.
• Personal computers (including laptop/notebook computers) have a connected monitor,
keyboard and CPU, and have developed into a convenient and flexible business tool
capable of operating independently or as part of an organisational network.
• Mobile devices such as personal digital assistants or the latest generation of cellular
telephones, offer maximum portability plus wireless connection to the internet,
although they do not offer the full functionality of a PC.
And we are already moving into the age of wearable computers for medical or security
applications, embedded computers in appliances ranging from motor cars to washing
machines, and the smart card which will provide identification, banking facilities, medical
records and more!
4. 1 Input devices
Data may enter an information system in a variety of different ways, and the input device that
is most appropriate will usually depend on the type of data being entered into the system, how
frequently this is done, and who is responsible for the activity. For example, it would be more
efficient to scan a page of typed text into an information system rather than retyping it, but if
this happens very seldom, and if typing staff are readily available, then the cost of the scanner
might not be justified. However, all of the input devices described in this chapter have at
least one thing in common: the ability to translate non-digital data types such as text, sound or
graphics into digital (i.e. binary) format for processing by a computer.
4.1.1 The keyboard
A lot of input still happens by means of a keyboard. Usually, the information that is entered
by means of a keyboard is displayed on the monitor. The layout of most keyboards is similar
Discovering Information Systems 35
4. Hardware
Section II
B ^B I' B ^1 ^1 B H ^1 ^1
ir^^llllllll
^■11111
iieiii s
to that of the original typewriter on which it was modelled.
Ironically, this "QWERTY" keyboard layout was originally
designed to slow the operator down, so that the keys of the
typewriter would not get stuck against each other. This
layout now works counter-productively since a computer can
process keyboard input many times faster than even the
fastest typist can manage. A number of attempts have been
made to design alternative layouts by rearranging the keys (the Dvorak keyboard) or by
reducing the number of keys. None of these alternative designs has really caught on. Special
keyboards have also been designed for countries that use a non-Roman alphabet, and also for
disabled people.
4.1.2 Pointing devices
The now ubiquitous electronic mouse is an essential input device for use with any graphical
user interface. It consists of a plastic moulded housing, designed to
fit snugly in the palm of the hand, with a small ball at its
bottom. Moving the mouse across a flat surface will translate
the movements into a rolling action of the ball. This is
translated into electronic signals that direct the corresponding movement of a cursor on the
computer monitor. Buttons on the mouse can then be used to select icons or menu items, or
the cursor can be used to trace drawings on the screen.
The less popular trackball operates exactly like an "upside-down" mouse except that the ball
is much larger and, instead of the mouse being moved over a surface, the user manipulates the
ball directly. Since the trackball can be built into the side of the keyboard, it obviates the need
for a free surface area and is therefore handy in situations
where desktop surface area is at a premium or not available.
Originally popular in educational laboratory settings and
for laptop computers, trackballs are now mainly confined to
exhibition displays and other public terminals.
Touch-screens are computer monitors that incorporate sensors on the screen panel
itself or its sides. The user can indicate or select an area or location on the screen by pressing
a finger onto the monitor. Light and touch pens work on a similar principle, except that a
stylus is used, allowing for much finer control. Touch pens are more commonly used with
handheld computers such as personal organisers or digital assistants. They have a pen-based
interface whereby a stylus (a pen without ink) is used on the small touch-sensitive screen of
the handheld computer, mainly by means of ticking off pre-defined options, although the
fancier models support data entry either by means of a stylised alphabet, which resembles a
type of shorthand, or some other more sophisticated handwriting recognition interface.
Digitiser tablets also use a pressure sensitive area with a
stylus. This can be used to trace drawings. A similar
conceptual approach is used for the touch pad that can be
found on the majority of new notebook computers, replacing
the more awkward joystick or trackball. The user controls the
36
[Free reproduction for educational use granted]
© Van Belle, Eccles & Nash
Section II 4. Hardware
cursor by moving a finger across a fairly small rectangular touch-sensitive area below the
keyboard, usually about 5 cm by 7 cm.
A large number of game interfaces have been developed to provide a more realistic and
natural interface in various gaming situations and simulations: the joy stick, steering wheel,
foot pedal and other gaming devices. They all perform functions similar to the mouse in that
they allow the user to control a cursor or simulate generally real-time motion control. Contact
your nearest game arcade for details.
Although the data glove also fits under the previous category, it is technically a lot more
complex. It looks like a hand glove but contains a large number of sensors and has a data
cable attached; though the latter is being replaced by means of infrared cordless data
transmission. Not only does the data glove allow for full three-dimensional movement but it
also senses the position of individual fingers, translating this into a grip. The glove is
currently used in virtual reality simulators where the user moves around in an artificially
rendered environment projected onto tiny LCD screens fitted into vision goggles. The
computer generates various imaginary objects, which the user can "pick up" and manipulate
by means of the glove. Advanced models even allow for tactile feedback by means of small
pressure pockets built into the glove.
4.1.3 Optical scanners and readers
There are a number of different optical scanner technologies on the market.
(5 Optical Scanners use light-emitting devices to illuminate the printing on paper.
Depending on how much light is reflected, a light-sensor determines the
position and darkness (or colour) of the markings on the paper. Special-
purpose optical scanners are in use by postal services to read and /
interpret hand-written postal codes. General-purpose scanners are
used with personal computers to scan in images or text. These vary
from handheld devices (see picture) to flatbed scanners which feed input
documents one sheet at a time. A common use of optical scanners is the scanning of
black-and-white or colour images and pictures. When scanning text, it is necessary to load
additional optical character recognition (OCR) software that converts the scanned raster-
image of the text into the equivalent character symbols, so that they can be edited using
word processing software.
(5 Barcode scanners detect sequences of vertical lines of different widths, the ubiquitous
barcode as found also on the back of this book. These scanners have become very popular
with retailers due to the fact that all pre-packaged products are now required to have a
product bar code on their packaging, following the standard laid down by the South
African Article Numbering Association (SAANA). Libraries and video shops now also
commonly use bar code scanners. They are more generally used for tracking and routing
large numbers of physical items such as for asset inventory purposes in many larger
organisations, postal items by the postal services and courier services, or for luggage
handling by airlines.
Discovering Information Systems 37
4. Hardware Section II
(5 Optical mark readers are capable of reading dark marks on specially designed forms. The
red multiple choice answer sheets in use at many educational and testing institutions are a
good example.
4.1.4 Other input devices
A magnetic card reader reads the magnetised stripe on the back of plastic credit-card size
cards. These cards need to be pre-recorded following certain standards. Although the cards
can hold only a tiny amount of information, they are very popular for access (door) control
and financial transactions (ATMs and point-of-sale terminals).
Magnetic ink character recognition (MICR) uses a special ink (containing magnetisable
elements) and a distinct font type. It is used mainly in the banking sector for the processing of
cheques.
Touch-tone devices can use a voice telephone to contact computer-based switchboards or
enter information directly into remote computers. Many corporate telephone help-lines rely on
the customer pressing the touch-tone telephone buttons to route his/her call to the correct
operator by selecting through a menu of possible options. South African banks also enable
their clients to perform a number of banking transactions via telephone.
Digital cameras allow you to make pictures of physical objects directly in a digital, i.e.
computer-readable, format. Relatively low-cost digital still picture cameras are now available
that capture images directly on electronic disk or RAM media instead of the traditional film.
Apart from being very compact, most of these digital cameras can also interface directly with
personal computers and are thus becoming a popular tool to capture pictures for e-mailing or
loading on the world-wide Web.
Biometric devices are used to verify personal identity based on fingerprints, iris or retinal
scanning, hand geometry, facial characteristics etc. A scanning device is used to capture key
measurements and compare them against a database of previously stored information. This
type of authentication is becoming increasingly important in the control of physical access.
Finally, voice input devices are coming of age. Voice-recognition has recently made a strong
entry into the market with the availability of low-cost systems that work surprisingly well
with today's personal computers. These systems allow for voice control of most standard
applications (including the operating system). With voice control, the computer recognises a
very limited number (50 or less) of frequently used, programmable system commands
("save", "exit", "print"...) from a variety of users. In fact, these systems are not only used for
the interface of computer programs; they are also slowly making an appearance in consumer
appliances, novelty items and even motor cars!
Much more difficult to achieve than voice control, is true voice dictation used to dictate e.g. a
letter to your word processor. The difficulty is that the computer must not only distinguish
between many tens of thousands of possible words, but it must also recognise the almost
unnoticeable breaks in between words, different accents and intonations. Therefore, voice
dictation typically requires a user to train the voice recognition software by reading standard
38 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II
4. Hardware
texts aloud. Nevertheless, for personal purposes and slow typists, voice recognition is rapidly
becoming a viable alternative to the keyboard.
4.2 Central Processing Unit (CPU)
Once data has been entered into a computer, it is acted on by the CPU, which is the real brain
of the computer. The CPU takes specific program instructions (usually one at a time), applies
them to the input data and transforms the input into output.
4.2.1 Components of the CPU.
The CPU has two major components.
• The Arithmetic and Logic Unit (ALU) executes the actual instructions. It knows how
to add or multiply numbers, compare data, or convert data into different internal
formats.
• The Control Unit does the "housekeeping" i.e. ensures that the instructions are
processed on time, in the proper sequence, and operate on the correct data.
Figure 4-1 gives a detailed representation of a computer system.
INPUT
DEVICES
Figure 4-1: Detailed view of a
4.2.2 Types of CPUs
MAIN or PRIMARY STORAGE
CENTRAL PROCESSING UNIT
CONTROL
UNIT
ARITHMETIC
LOGIC
UNIT
SECONDARY
STORAGE
DEVICES
OUPUT
DEVICES
computer system.
The CPU is an electronic device based on microchip technology, hence it is also often called
the microprocessor. It is truly the showcase and culmination of the state-of-the-art in the
electronics industry: a tiny silicon-based chip occupying less than 1 square cm contains
several millions of transistor elements, measuring less than a thousandth of a millimetre
across. They operate at speeds way beyond our comprehension: a typical CPU can multiply
more 7-digit numbers in one second than a human could do in ten lifetimes, but uses less
energy than a light bulb!
Think of the motor car industry: there are different manufacturers or makes of cars
(Volkswagen, Toyota, etc.), each with different models (Golf, Jetta, ...), which come out in
different versions (City Golf, Sports model, coupe, etc.). In addition, there exist custom-made
Discovering Information Systems
39
4. Hardware Section II
special-purpose cars. It is the same in the computer chip business. There are many different
types of CPUs on the market. The best-known manufacturer is Intel, which produces the
microprocessors for the IBM-compatible personal computer (PC). Some of its competitors
produce clones or imitations (e.g. AMD), others manufacturers produce different types of
microprocessors or concentrate on small volumes of highly specialised or very fast
microprocessors. Intel has produced a large number of CPU types: the earliest model used in
the Personal Computer was the 8088, followed by the 8086, the 80286, the 386, 486 and the
line of Pentium processors.
4.2.3 Speed of processing
How does one measure the speed of, say a Porsche 911? One could measure the time that it
takes to drive a given distance e.g. the 900 km from Cape Town to Bloemfontein takes 4'/2
hours (ignoring speed limits and traffic jams). Alternatively, one can indicate how far it can
be driven in one standard time unit e.g. the car moves at a cruising speed of 200 km/hour.
In the same way, one can measure the speed of the CPU by checking the time it takes to
process one single instruction. As indicated above, the typical CPU is very fast and an
instruction can be done in about two billionths of a second. To deal with these small fractions
of time, scientists have devised smaller units: a millisecond (a thousandth of a second), a
microsecond (a millionth), a nanosecond (a billionth) and a picosecond (a trillionth).
However, instead of indicating the time it takes to execute a single instruction, the processing
speed is usually indicated by how many instructions (or computations) a CPU can execute in
a second. This is exactly the inverse of the previous measure; e.g. if the average instruction
takes two billionths of a second (2 nanoseconds) then the CPU can execute 500 million
instructions per second (or one divided by 2 billionths). The CPU is then said to operate at
500 MIPS or 500 million of instructions per second. In the world of personal computers, one
commonly refers to the rate at which the CPU can process the simplest instruction (i.e. the
clock rate). The CPU is then rated at 500 MHz (megahertz) where mega indicates million and
Hertz means "times or cycles per second". For powerful computers, such as workstations,
mainframes and supercomputers, a more complex instruction is used as the basis for speed
measurements, namely the so-called floating-point operation. Their speed is therefore
measured in megaflops (million of floating-point operations per second) or, in the case of
very fast computers, teraflops (billions of flops).
In practice, the speed of a processor is dictated by four different elements: the "clock speed",
which indicates how many simple instructions can be executed per second; the word length,
which is the number of bits that can be processed by the CPU at any one time (64 for a
Pentium IV chip); the bus width, which determines the number of bits that can be moved
simultaneously in or out of the CPU; and then the physical design of the chip, in terms of the
layout of its individual transistors. The latest Pentium processor has a clock speed of about 4
GHz and contains well over 100 million transistors. Compare this with the clock speed of 5
MHz achieved by the 8088 processor with 29 000 transistors!
Moore's Law (see Figure 4-2) states that processing power doubles for the same cost
approximately every 18 months.
40 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II
4. Hardware
Pentium 4
Pentium III ^J|
Transistors
100,000,000
10,000,000
1,000,000
100,000
10,000
1,000
486 DX
Pentium ^,
Pentium II
386
8086^^**
4004 8008*'
#^8080
1970 1975 1980 1985 1990 1995 2000
Figure 4-2. Illustration of Moore 's Law
4.2.4 Von Neumann versus Parallel CPU Architecture
The traditional model of the computer has one single CPU to process all the data. This is
called the Von Neumann architecture because he engineered this approach to computers in the
days when computers were still a dream.
Except for entry-level personal computers, most computers now have two, four, or up to
sixteen CPUs sharing the main processing load, plus various support processors to handle
maths processing, communications, disk I/O, graphics or signal processing. In fact many CPU
chips now contain multiple "cores" each representing an individual CPU.
Some super-computers that have been designed for massive parallel processing, have up to
64,000 CPUs. These computers are typically used only for specialised applications such as
weather forecasting or fluid modelling. Today's supercomputers are mostly clusters (tight
networks) of many thousands of individual computers.
4.2.5 Possible Future CPU Technologies
Perhaps the major future competitor of the microchip-based microprocessor is optical
computing. Although the technology for developing electronic microchips suggests that CPUs
will continue to increase in power and speed for at least the next decade or so, the physical
limits of the technology are already in sight. Switching from electronic to light pulses offers a
number of potential advantages: light (which consists of photons) can travel faster, on
narrower paths and does not disperse heat. In theory, one can even process different signals
(each with a different light frequency) simultaneously using the same channel. Although the
benefits of optical processing technology have already been proven in the areas of data
storage (CD-Rom, CD-R) and communication (fibre optics), the more complex all-optical
switches required for computing are still under development in the research laboratories.
A very experimental alternative to optical and electronic technologies is the organic
computer. Research indicates that, for certain applications, it is possible to let a complex
organic molecule act as a primitive information processor. Since even a tiny container filled
Discovering Information Systems
41
4. Hardware Section II
with the appropriate solutions contains many trillions of these molecules, one obtains in effect
a hugely parallel computer. Although this type of computer can attack combinatorial
problems way beyond the scope of traditional architectures, the main problem is that the
programming of the bio-computer relies entirely on the bio-chemical properties of the
molecules.
Another exciting but currently still very theoretical development is the possible use of
quantum properties as the basis for a new type of computer architecture. Since quantum states
can exist in juxtaposition, a register of qubits (a bit value in quantum state) takes on all the
possible values simultaneously until it is measured. This could be exploited to speed up
extremely parallel algorithms and would affect such areas as encryption, searching and error-
correction. To date, experimental computers with a few qubits have been built but the
empirical validation of the actual usefulness of quantum computing still remains an open
question.
4.3 Main Memory
The function of main memory (also referred to as primary memory, main
storage or internal storage) is to provide temporary storage for
instructions and data during the execution of a program. Main memory is
usually known as RAM, which stands for Random Access Memory.
Although microchip-based memory is virtually the only technology used by today's
computers, there exist many different types of memory chips.
4.3.1 Random Access Memory (RAM)
RAM consists of standard circuit-inscribed silicon microchips that contain many millions of
tiny transistors. Very much like the CPU chips, their technology follows to the so-called law
of Moore, which states that they double in capacity or power (for the same price) every 18
months. A RAM chip easily holds hundreds of Megabytes (million characters). They are
frequently pre-soldered in sets on tiny memory circuit boards called SIMMS (Single In-line
Memory Modules) or DIMMS (Dual ...) which slot directly onto the motherboard: the main
circuit board that holds the CPU and other essential electronic elements. The biggest
disadvantage of RAM is that its contents are lost whenever the power is switched off.
There are many special types of RAM and new acronyms such as EDO RAM, VRAM etc. are
being created almost on a monthly basis. Two important types of RAM are:
(S Cache memory is ultra-fast memory that operates at the speed of the CPU. Access to
normal RAM is usually slower than the actual operating speed of the CPU. To avoid
slowing the CPU down, computers usually incorporate some more expensive, faster cache
RAM that sits in between the CPU and RAM. This cache holds the data and programs that
are needed immediately by the CPU. Although today's CPUs already incorporate an
amount of cache on the circuit itself, this on-chip cache is usually supplemented by an
additional, larger, cache on the motherboard.
S Flash RAM or flash memory consists of special RAM chips on a separate circuit board
within a tiny casing. It fits into custom ports on many notebooks, hand-held computers
42 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 4. Hardware
and digital cameras. Unlike normal RAM, flash memory is non-volatile i.e. it holds it
contents even without external power, so it is also useful as a secondary storage device.
4.3.2 Read-Only Memory (ROM)
A small but essential element of any computer, ROM also consists of electronic memory
microchips but, unlike RAM, it does not lose its contents when the power is switched off. Its
function is also very different from that of RAM. Since it is difficult or impossible to change
the contents of ROM, it is typically used to hold program instructions that are unlikely to
change during the lifetime of the computer. The main application of ROM is to store the so-
called boot program: the instructions that the computer must follow just after it has been
switched on to perform a self-diagnosis and then tell it how load the operating system from
secondary storage. ROM chips are also found in many devices which contain programs that
are unlikely to change over a significant period of time, such as telephone switch boards,
video recorders or pocket calculators. Just like RAM, ROM comes in a number of different
forms:
(5 PROM (Programmable Read-Only Memory) is initially empty and can be custom-
programmed once only using special equipment. Loading or programming the contents of
ROM is called burning the chip since it is the electronic equivalent of blowing tiny
transistor fuses within the chip. Once programmed, ordinary PROMs cannot be modified
afterwards.
(5 EPROM (Erasable Programmable Read-Only Memory) is like PROM but, by using
special equipment such as an ultra-violet light gun, the memory contents can be erased so
that the EPROM can be re-programmed.
(5 EEPROM (Electrically Erasable Programmable Read-Only Memory) is similar to
EPROM but it can be re-programmed using special electronic pulses rather than ultra-
violet light so no special equipment is required.
4.4 Secondary Storage Devices
Since the main memory of a computer has a limited capacity, it is necessary to retain data in
secondary storage between different processing cycles. This is the medium used to store the
program instructions as well as the data required for future processing. Most secondary
storage devices in use today are based on magnetic or optical technologies.
4.4.1 Disk drives
The disk drive is the most popular secondary storage device, and is found in both mainframe
and microcomputer environments. The central mechanism of the disk drive is a flat disk,
coated with a magnetisable substance. As this disk rotates, information can be read from or
written to it by means of a head. The head is fixed on an arm and can move across the radius
of the disk. Each position of the arm corresponds to a "track" on the disk, which can be
visualised as one concentric circle of magnetic data. The data on a track is read sequentially
as the disk spins underneath the head. There are quite a few different types of disk drives.
Discovering Information Systems 43
4. Hardware Section II
In Winchester hard drives, the disk, access arm and read/write heads are combined in one
single sealed module. This unit is not normally removable, though there are some models
available where the unit as a whole can be swapped in and out of a specially designed drive
bay. Since the drives are not handled physically, they are less likely to be contaminated by
dust and therefore much more reliable. Mass production and technology advances have
brought dramatic improvements in the storage capacity with Terabyte hard drives being state
of the art at the end of 2006. Current disk storage costs as little Rl per gigabyte.
Large organisations such as banks, telcos and life insurance companies, require huge amounts
of storage space, often in the order of many terabytes (one terabyte is one million megabytes
or a trillion characters). This was typically provided by a roomful of large, high-capacity hard
drive units. Currently, they are being replaced increasingly by redundant arrays of
independent disks (RAIDs). A RAID consists of an independently powered cabinet that
contains a number (10 to 100) of microcomputer Winchester-type drives but functions as one
single secondary storage unit. The advantage of the RAID is its high-speed access and
relatively low cost. In addition, a RAID provides extra data security by means of its fault-
tolerant design whereby critical data is mirrored (stored twice on different drives) thus
providing physical data redundancy. Should a mirrored drive fail, the other drive steps in
automatically as a backup.
A low-cost, low-capacity version of the hard disk was popularised by
the microcomputer. The diskette consists of a flexible, magnetic
ti^J surface coated mylar disk inside a thin, non-removable, plastic
sleeve. The early versions of the diskette were fairly large (8" or
5W) and had a flexible sleeve, hence the name floppy diskette. These
have rapidly been replaced by a diskette version in a sturdier sleeve, the
stiffy disk, that despite its smaller size (3 W') can hold more data. Although the popular IBM
format only holds 1,44 megabytes, a number of manufacturers have developed diskette drives
that can store from 100 to 250 megabytes per stiffy. An alternative development is the
removable disk cartridge, which is similar in structure to an internal hard drive but provides
portability, making it useful for backup purposes.
4.4.2 Magnetic tape
While disk and optical storage have overtaken magnetic tape as
the most popular method of storing data in a computer, tape is still
used occasionally - in particular for keeping archive copies of
important files.
The main drawback of magnetic tape is that it is not very efficient for accessing data in any
way other than strictly sequential order. As an illustration, compare a CD player (which can
skip to any track almost instantly) with a music tape recorder (which has to wind the tape all
the way through if one wants to listen to a song near the end). In computer terms, the ability
to access any record, track, or even part within a song directly is called the direct access
method. In the case of the tape recorder one may have to wind laboriously through the tape
until one reaches the song required - this is referred to as the sequential access method.
44 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 4. Hardware
The high-density diskette and recordable optical disk have all but eroded the marginal cost
advantage that tape storage enjoyed. This technology is therefore disappearing fast.
4.4.3 Optical disk storage
Optical disks, on the other hand, are rapidly becoming the storage medium of choice for the
mass distribution of data/programs and the backup of data. Similar
to disk storage, information is stored and read from a circular disk.
However, instead of a magnetic read head, a tiny laser beam is
V ^1 used to detect microscopic pits burnt onto a plastic disk coated
^^r with reflective material. The pits determine whether most of the
^^k j^0Zm*/>^ \ laser light is reflected back or scattered, thus making for a binary
^•\ \ ^r "on'* or "off. In contrast to hard disks, data is not stored in
^^r concentric cylinders but in one long continuous spiral track.
Trivial fact: The spiral track used to store data on a CD is over six kilometres long.
A popular optical disk format is the 12-cm CD-ROM. The widespread use of music compact
discs has made the technology very pervasive and cheap. Production costs for a CD-ROM are
less than Rl, even for relatively small production volumes. The drive reader units themselves
have also dropped in price and are now hardly more than the cost of a diskette drive. A
standard CD-ROM can store 650 megabytes of data and the data can be transferred at many
megabytes per second, though accessing non-sequential data takes much longer.
The CD-ROM is a read-only medium. Data cannot be recorded onto the disk. The low cost
and relatively large capacity makes the CD-ROM ideally suited to the distribution of
software. They are also ideal for the low-cost distribution of large quantities of information
such as product catalogues, reference materials, conference proceedings, databases, etc. It is
indispensable for the storage of multimedia where traditional textual information is
supplemented with sound, music, voice, pictures, animation, and even video clips.
The limitation of the read-only format lead to the development of low-cost recordable optical
disks. The compact disk recordable (CD-R) is a write-once, read-many (WORM) technology.
The CD-R drive unit takes a blank optical disk and burns data onto it using a higher-powered
laser. This disk can then be read and distributed as an ordinary CD-ROM, with the advantage
that the data is non- volatile i.e. permanent. The rapid drop in the cost of drive units and blank
recording media (less than R2 per CD-R) is making this a very competitive technology for
data backup and small-scale data distribution.
Although the 650 megabytes initially seemed almost limitless, many multimedia and video
applications now require more storage. A new format, the Digital Video Data (DVD) standard
increased the capacity of the CD-ROM by providing high-density, double-sided and double-
layered CDs. By combining the increased storage capacity with sophisticated data
compression algorithms, a DVD disc can easily store 10 times as much as a CD, sufficient for
a full-length high-quality digital motion picture with many simultaneous sound tracks.
Even the DVD is not sufficient storage capacity and currently two optical technologies have
Discovering Information Systems 45
4. Hardware
Section II
been developed to increase storage capacity even further. The basic specification of both HD-
DVD and Blu-Ray provide for more than 25 GB of storage on a disc although multi-layer
Blu-Ray discs with capacities of more than 200 GB have already been developed.
A promising research area involves the use of holographic disk storage whereby data is stored
in a three-dimensional manner. Though in its infancy, early prototypes promise a many-fold
increase in storage capacity and it could become the answer to the ever increase storage
requirements of the next decade
Device
Access Speed
Capacity
Cost
RAM
< 2 nanosec
256 MB (chip)
<R1/MB
Tape
serial only
500 MB-4 GB
<10c/MB
Diskette (3 W)
300 ms
1,44 MB
Rl/MB
PC hard disk
10 ms
40-750 GB
<2c/MB
M/F hard disk
25 ms
100+ GB
R2/MB
CD-ROM
< 100 ms
660 MB
<0.1c/MB
CD-R
< 100 ms
660 MB
<0.2c/MB
DVD
< 100 ms
8 GB
<0.1c/MB
HD-DVD
< 100 ms
30 GB
?
Blu-Ray
< 100 ms
25 GB-200GB
?
Figure 4-3: Comparison of secondary storage devices
4.5 Output Devices
The final stage of information processing involves the use of output devices to transform
computer-readable data back into an information format that can be processed by humans. As
with input devices, when deciding on an output device you need to consider what sort of
information is to be displayed, and who is intended to receive it.
One distinction that can be drawn between output devices is that of hardcopy versus softcopy
devices. Hardcopy devices (printers) produce a tangible and permanent output whereas
softcopy devices (display screens) present a temporary, fleeting image.
4.5.1 Display screens
The desk-based computer screen is the most popular output device. The standard monitor
works on the same principle as the normal TV tube: a "ray" gun fires
electrically charged particles onto a specially coated tube (hence the
name Cathode-Ray Tube or CRT). Where the particles hit the coating,
the "coating" is being "excited" and emits light. A strong magnetic field
guides the particle stream to form the text or graphics on your familiar
monitor.
CRTs vary substantially in size and resolution. Screen size is usually measured in inches
diagonally across from corner to corner and varies from as little as 12 or 14 inches for
standard PCs, to as much as 40+ inches for large demonstration and video-conferencing
screens. The screen resolution depends on a number of technical factors.
46
[Free reproduction for educational use granted]
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Section II 4. Hardware
A technology that has received much impetus from the fast-growing laptop and notebook
market is the liquid crystal display (LCD). LCDs have matured quickly, increasing in
resolution, contrast, and colour quality. Their main advantages are lower energy requirements
and their thin, flat size. Although alternative technologies are already being explored in
research laboratories, they currently dominate the "flat display" market.
Organic light-emitting diodes (OLED) can generate brighter and faster images than LED
technology, and require thinner screens, but they have less stable colour characteristics,
making them more suitable for cellular telephone displays than for computers.
Another screen-related technology is the video projection unit. Originally developed for the
projection of video films, the current trend towards more portable LCD-based lightweight
projectors is fuelled by the needs of computer-driven public presentations. Today's units fit
easily into a small suitcase and project a computer presentation in very much the same way a
slide projector shows a slide presentation. They are rapidly replacing the flat transparent LCD
panels that needed to be placed on top of an overhead projection unit. Though the LCD panels
are more compact, weigh less and are much cheaper, their image is generally of much poorer
quality and less bright.
4.5.2 Printers and plotters
Printers are the most popular output device for producing permanent, paper-based computer
output. Although they are all hardcopy devices, a distinction can be made between impact and
non-impact printers. With impact printers, a hammer or needle physically hits an inked ribbon
to leave an ink impression of the desired shape on the paper. The advantage of the impact
printer is that it can produce more than one simultaneous copy by using carbon or chemically-
coated paper. Non-impact printers, on the other hand, have far fewer mechanically moving
parts and are therefore much quieter and tend to be more reliable.
The following are the main types of printers currently in use.
S Dot-matrix printers used to be the familiar low-cost printers connected to many personal
computers. The print head consists of a vertical row of needles each of which is
individually controlled by a magnet. As the print head moves horizontally across the
paper, the individual needles strike the paper (and ribbon
in between) as directed by the control mechanism to
produce text characters or graphics. A close inspection of a
dot-matrix printout will reveal the constituent dots that
make up the text. Although it is one of the cheapest printer options, its print quality is
generally much lower that that of laser and ink-jet printers. However, today's models are
quick and give a much better quality by increasing the number of needles.
(5 Laser printers are quickly growing in market share. They work on the same principle as
the photocopier. A laser beam, toggled on and off very quickly, illuminates selected areas
on a photo-sensitive drum, where the light is converted into electrical charge. As the drum
rotates into a "bed" of carbon particles ("toner") with the opposite charge, these particles
will adhere to the drum. The blank paper is then pressed against the drum so that the
Discovering Information Systems 47
4. Hardware
Section II
particles "rub off onto the paper sheet. The sheet then passes
through a high-temperature area so that the carbon particles are
permanently fused onto the paper. Current high-end laser
printers can cope with extremely large printing volumes, as
is required e.g. by banks to print their millions of monthly
account statements. The laser technology continues to
develop in tandem with photocopier technology. Laser printers can now handle colour
printing, double-sided printing or combine with mail equipment to perforate, fold, address
and seal automatically into envelopes. At the lower end of the scale are the low-cost
"personal" laser printers, which give a very good printing quality at a relatively modest
cost.
(S Thermal printers use heat to print. The older thermal printers used heat-sensitive paper,
similar to the special fax paper. A slight heat or pressure will leave a darker area. This
produced very cheap but low-quality output. Currently, thermal-printing technology is
used mainly for high-quality colour printing. These new thermal printers use coloured
wax sticks and melt the wax onto the paper. Although they are slower than competing
colour laser and inkjet technologies, they give a much more vibrant, colour-saturated
image.
(5 Inkjet printers are probably the most popular low-cost printing technology. Liquid ink is
squirted onto the paper in the form of tiny droplets. These printers are about the same
price as dot-matrix printers, albeit more expensive in terms of consumables. Their quality
is close to that of the laser printers. Their great advantage is that the printers can easily be
adapted to use coloured ink, thus making popular colour printers.
(5 Plotters are mainly used for engineering and architectural
drawings. A plotter consists of one (or several - in the case of
colour plotters) pen(s) affixed to an arm. As the arm moves
across the sheet of paper, the pen draws lines onto the paper. It is
ideal for line drawings such as plans, especially in cases where
the paper size exceeds that which can be accommodated by the
other types of printers.
(S Chain and line printers are still popular in mainframe environments for the quick
production of large volumes of internal printing. The line printer consists of a horizontal,
rotating "drum" with 132 cylinders, each containing a full character set. As the 132-
column wide paper moves up past the drum, a line at a time, each one of the 132 hammers
on the other side of the paper strikes at the exact moment that the corresponding cylinder
"shows" the correct character. The hammer hits the drum (and ink ribbon) and leaves an
imprint of the character on the paper. The chain printer works on the same principle, but
uses a horizontally rotating chain with engraved characters, instead of a drum. As anyone
with some working experience in a large organisation knows, the print quality of these
"computer printouts" is not very high.
48
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Section II
4. Hardware
Figure 4-4 compares the various output devices in terms of a number of characteristics.
Device
Technology
Quality
Speed
Dupli-
cates?
Graph
ics?
Fonts?
Colour?
CRT
softcopy
High
Very
fast
NA
yes
yes
yes
LCD
softcopy
Fair
Very
fast
NA
yes
yes
yes
Plotter
hardcopy
Fair
Slow
no
yes
yes
yes
Chain/ line
printer
hardcopy
Low
Very
Fast
yes
no
no
no
Laser printer
hardcopy
High
Fast/
fair
no
yes
yes
yes
Dot-Matrix
printer
hardcopy
Fair
Fast/
fair
yes
yes
yes
some
Inkjet printer
hardcopy
Good
Fair
no
yes
yes
yes
Figure 4-4: Comparison of output devices
4.5.3 Audio-output devices
A type of output that is becoming increasingly popular
different types of audio output.
is
audio output. There are many
(5 Sound output is required by most multimedia applications and sophisticated games. The
sound card in many of today's personal computers synthesises sound by drawing from a
library of stored sounds, essentially using the same process as found in music keyboards.
More advanced multimedia workstations are equipped for full stereo multi-channel
surround sound and easily surpass many a modern hi-fi system in cabling and speaker
complexity.
(S MIDI in/output. Modern day music production would be impossible without a vast array
of electronic instruments and keyboards. These are typically controlled by a personal
computer by means of Musical Instrument Digital Interface (MIDI), a common standard
for linking, controlling and processing electronic music.
(5 Speech synthesis is the production of speech-like output using an artificial voice.
Although the lack of intonation still makes the voice sound artificial, the technology is
reasonably mature and can be found anywhere from talking clocks and luxury cars to
automated responses for telephonic directory enquiries.
4.5.4 Other Output Devices
Many other, extremely specialised input and output devices have been developed. Process
control, for example, is a very specialised field but extremely important for automated
factories (car manufacturing, canneries), continuous process environments (nuclear plants,
refineries) or hazardous places (microbiological research laboratories, space exploration). For
these applications, the computer relies on a multitude of sensors for its inputs: temperatures,
speed, pressure, flow rates, weight, position, . . . These sensor inputs are then processed by the
Discovering Information Systems
49
4. Hardware Section II
computers, which in turn control directly robot arms and other mechanical devices such as
cutters, welding equipment, valves, switches, mixers etc.
4.6 South African Perspective
A number of car manufacturers have introduced new model vehicles that optionally includes a
vehicle safety system that could reduce road deaths and injuries by foreseeing an unavoidable
collision and activating passenger restraint and protection systems before it happens. "Pre-
crash safety" has three elements:
• A sensor uses millimetre- wave radar to detect vehicles and obstacles on the road
ahead.
• An electronic control unit (ECU) determines whether a collision is imminent based on
the position, speed and course of the object. If it is...
• The seat belts retract to pull the passengers back into their seats and emergency brake
assistance pressure is built, ready for the driver to hit the pedal.
Until now, vehicle safety devices have only been able to activate after a collision.
The car's radar, Toyota says, works even in rain and snow and is constantly scanning ahead.
Newly developed computer software can quickly determine whether a collision is imminent
based on the expected course of the host vehicle as well as the position, speed and expected
course of preceding or oncoming vehicles. This could be the solution we need for South
Africa's unacceptably high road death rate - all we need is for every South African driver to
be able to afford the new Toyota!
4. 7 Beyond the Basics
Commercial development is set to begin on the next generation of memory: the samarium
cube. This technology will allow the storage of up to one terabyte (1000 gigabytes) of data in
a cubic centimetre of glass. When an extremely short pulse of laser light is applied to a piece
of glass containing the rare earth element samarium, a dot around 400 nanometers in diameter
becomes luminous, allowing the glass to be used as an optical memory. These luminous dots
can be spaced 100 nanometers apart, and up to 2000 layers of dots can be stored and read
within a cubic centimetre of glass, producing a three-dimensional storage medium. The pulse
of light used to irradiate the cube lasts for only 1000-trillionth of a second (a femtosecond),
because a longer pulse of light will create heat that can cause the glass to crack.
4.8 Exercises
4.8.1 PC specifications
A friend of yours wants to buy a personal computer for her small, home-based
service business. She wants to use industry-standard software to create brochures, do
accounts and financial calculations and maintain a database of customers, suppliers,
products and orders. She copied down the specifications for a computer that she saw
advertised on TV at a competitive price, but she is not sure whether she would really
50 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II
4. Hardware
need all the components, and she doesn't understand all the technical "buzzwords".
As a knowledgeable friend, she has asked you
• to explain in non-technical terms her questions about the various components;
• to identify any obviously incorrect specifications that she might have copied
down wrongly from the advertisement, and briefly explain why they are wrong.
The following is her specifications sheet:
Specification
Question
Correct?
1.7GHzPentium-IV
What does "1.7 GHz" mean?
4 MB RAM
What is RAM used for?
500 GB Hard Disk
What sort of things would be stored on the hard disk?
X50 CD-ROM
Would I use this to make backups? If not, what would
I use it for?
32 MB SVGA Graphics
card
What does this do?
Stiffy drive
Why do I need one if I have a CD-ROM?
102 keyboard
Should I get any other input devices as well?
14" monitor
Is this likely to be a modern flat screen like you get on
laptops, or the old fashioned sort of monitor?
Colour inkjet printer
Why not get a dot-matrix printer?
4.8.2 Input / Output devices
A standard Automatic Teller Machine ("ATM") has a large number of input and output
devices. List as many of its I/O devices as you can (you may include sensors as well).
Discovering Information Systems
51
5. Software Section II
5. Software
The computer owes most of its success to its versatility. By loading a different set of
instructions, the same computer becomes a word processor, a games machine or a scientific
number-cruncher. The set of instructions that tells the computer what to do is called the
computer software or program).
The real purpose of a computer is to perform information-processing tasks for the user. Thus
the user will need to have application software such as an accounting package, word
processor, graphics design software, a game or a Web browser. Applications do not grow on
trees - they are complex products that have to be designed and coded very carefully.
Although it is possible in principle for users to develop their own application software, most
end-users leave this task to professional software designers. These software developers
require the use of a variety of development tools. Finally, since that all applications perform
certain common tasks such as printing, reading or saving data from disk, handling input
devices, etc, one single master program called the operating system has been developed to
relieve each individual program developer of these common tasks.
Regardless of the type of software being used, or the purpose that it is being used for, it will
have to provide some means for a human being to interact with it: to enter data or program
instructions, to request that a file be saved or printed, or simply to view the information that
has been produced. This function is performed by the user interface.
5. 1 The User Interface
The user interface relates to the presentation and formatting of information on the user's
screen, as well as the various methods available to the user of selecting data and initiating
actions. It controls the way the user and computer system interact, for example by means of
error messages or help functions.
Although application programmers are free to develop their own interface independently of
the operating system, most applications inherit or make use of the user interface functions
provided by the operating system. We will therefore illustrate the various generations of user
interfaces by means of examples of operating systems.
5.1.1 Command-based interface.
Figure 5-1 shows an example of a command-based interface. It demonstrates how the user
checks for the existence of a file before copying it onto her diskette, using Microsoft DOS
(MS-DOS). When using a command-based interface, the user has to remember (or look) up a
variety of commands and their various options or parameters, making it difficult for novice
users to operate. Other examples of command-based operating systems are UNIX (popular on
mini-computers, but even more cryptic than MS-DOS) and most mainframe operating
systems such as MVS or BS2000.
52 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II
5. Software
C:\TODO>dir * . jpg /w
Volume in drive C is UCT
Volume Serial Number is 3D63-14D1
Directory of C:\TODO
PAHEL1.JPG PAHEL2.JPG PAHEL3.JPG
PIC_003.JPG PIC_001.JPG PIC_004.JPG
PAHEL7.JPG PAHEL8.JPG VAN1.JPG
13 file(s) 638,161 bytes
0 dir(s) 708,476,928 bytes free
C:\TODO>copy vanl . jpg a:
Not ready reading drive A
Abort, Retry, Fail?r
Figure 5-1:
A sample MS-DOS session.
5.1.2 Menu-driven Interface
A menu-driven user interface allows the user to select from a menu, a predefined list of
available options or selections. This is already an improvement on the command-driven
interface, since the user no longer has to rely on memory to remember the available options or
commands. Many applications running under command-driven operating systems are menu-
driven. "Power-users" (very experienced or knowledgeable users) often prefer the command-
driven interface to a graphical alternative, because it allows a greater degree of customisation
and may be quicker. A menu-driven interface is also appropriate when you wish to limit the
functions that are available to users.
Figure 5-2 below shows an example of the Novell Netware S YSCON utility. Novell Netware
is a popular networking operating system.
SYSCON 3.68 Wednesday October 27, 1999 Z:4G pm
Usee JERNPAUL On File Server INFOSYS
Figure 5-2: A menu-based interface (Novell)
Discovering Information Systems
53
5. Software
Section II
5.1.3 Graphical User Interface
The graphical user interface (GUI) is currently the most popular interface on PCs. It requires a
high-resolution graphics monitor. The metaphor used in many GUIs is that of a "desktop" on
which various tools and documents are laid out. Active applications will have their own
window, which can be re-sized at will, often overlaying windows of other applications.
(Hence the name of the dominant GUI operating system, Microsoft Windows.) A window
typically contains a document (or at least as much it as will fit in the space) and a number of
tool and menu-bars. Options and commands on toolbars, as well as non-active applications or
documents on the desktop, are indicated by means of icons (small graphical symbols or
pictures). A GUI requires frequent use of the pointing device, usually a mouse, e.g. to move
items across windows, highlight portions of a document, select specific icons or pinpoint
destinations.
Figure 5-3 gives an example of a Windows desktop with a few applications open.
■.Mi].L,).L,.i]j.,..ui].i«i'BimaB»miu,!iai»Mji! m
Figure 5-3: A GUI (MS-Windows XP)
5.1.4 Pen-based Interface
Pocket computers, handheld computers and personal digital assistants (PDAs) are generally
too small to incorporate a keyboard. Instead, many combine the liquid crystal display (LCD),
which is the output screen, with a pressure sensitive layer that can be used for input. All user
input happens by means of a stylus or any pen-like pointing device. The pressure-sensitive
LCD pad is then used in the same way as one would use a writing tablet or clipboard. Most of
the interface consists of ticking off menu options, such as lists or timeslots on a diary.
However, many devices also employ advanced handwriting recognition software so that users
can actually enter words and numbers in their own handwriting.
54
[Free reproduction for educational use granted]
© Van Belle, Eccles & Nash
Section II 5. Software
5.1.5 Natural Language Interface
Voice input and output based on a limited set of stored sounds is readily available across all
computer platforms, and is widely used by the visually impaired, and for hands-free data
input. However, the ambition of a large number of computer scientists is to provide a
completely unrestricted natural language interface to computers. Although voice recognition
and voice synthesis are technically quite achievable, the major technical challenge remains to
interpret standard English language statements, because this would require actual
understanding or knowledge processing on behalf of the computer. This active area of
research is known as natural language processing (NLP). Although it has become relatively
standard practice to develop natural language interfaces for restricted subject domains, we are
still a long way from providing a natural language interface that can deal with the many
ambiguities of general life.
5.2 Application Software
The type of software with which users are in general most familiar, is application software -
programs such as word processors or salary packages that do specific jobs to improve
business productivity. Because of the big variety in user needs, there is a large multitude of
application software available. By comparison, there are only about 5 to 10 popular different
operating systems, and probably less than 100 different ones in use world-wide. If one looks
at development tools, there are about 20 to 100 fairly popular development platforms
available, although there are several thousands in use. But a quick scan of e.g. the web-site of
"shareware.com" will reveal tens if not hundreds of thousands of different applications, with
several thousands of commercial applications enjoying fairly widespread use. It is therefore
impractical to attempt to discuss each of the many different applications that are available.
Instead, this section will look at some of the many classification schemes used for various
types of application software.
5.2.1 Classification by Function
A popular way to classify applications is to distinguish them according to application area.
(5 General purpose, productivity or end-user applications assist a wide variety of users with
common information processing tasks such as number crunching, word processing,
business graphics, web browsing, electronic mail, scheduling or data management.
(5 Business applications aim to automate common, generic business functions or processes.
They include debtors, creditors, general ledger, inventory management, order entry and
sales processing.
(S Scientific applications are focussed on the needs of scientists and researchers: astronomy,
weather forecasting, geographical information systems (GIS), statistics, simulations,
engineering drawings, etc.
G Finally, there is a large category of miscellaneous applications that do not fit neatly in any
of the above categories, such as computer-based training software or games.
Trivial fact: Chess champion Gary Kasparov was beaten by a computer, Deep Blue, in 1997.
Discovering Information Systems 55
5. Software Section II
Deep Blue considered 200 million positions per second in order to evaluate alternative
outcomes before making each move.
5.2.2 Vertical vs Horizontal Classification
(S Vertical applications target a specific industry or sector with similar business processes.
Examples are packages for video store management, medical practice management,
pharmacists, retailers, commercial banks etc.
(S Horizontal applications are business applications that can be used by virtually any
business because of the universality of the business needs, e.g. accounting applications,
inventory management or debtors control.
(S Enterprise-wide systems, often called enterprise resource planning (ERP) systems, aim to
fulfil all the information system requirements of a business. These systems consists of
many different modules, covering all generic business processes, with a great degree of
standardisation of interfaces and an integrated, corporate database. Popular ERP vendors
are SAP, BAAN and PeopleSoft.
(S Inter-organisational systems (IOS) are systems that cross the boundaries of individual
organisations. Examples are electronic data interchange (EDI), electronic funds transfer
(EFT) or the Internet.
5.2.3 Organisational Level
A popular academic classification of functional business applications looks at the hierarchical
level of the organisation in which the software is used. This has already been discussed in
Chapter 1.
(S Transaction Processing Systems (TPS) perform the business process-related data-
processing tasks such as invoicing, statements, inventory, order and sales processing.
They assist mainly clerical staff.
(5 Management Information Systems (MIS) assist the operations and line managers with the
control of the business process activities, usually by means of standard, regular reports.
Virtually all TPS incorporate a MIS reporting module.
& Decision Support Systems (DSS) are more interactive applications that actually assist with
the decision making process of middle management (and professionals). Spreadsheets,
geographical information systems (GIS) and expert systems are good examples of DSS.
(S Executive Information/Support Systems (EIS or ESS) assist top-level executives with their
daily information needs for top management control as well as their strategic decision-
making.
5.3 System Development Software
Many end-users never come into contact with the software that was used to create their
applications (and operating systems). However, a good understanding of the alternative
56 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 5. Software
system development software options can help you in comparing different software packages,
or in making the decision whether to have an application custom-developed for a particular
business need.
5.3.1 Programming languages, source code and compilers
The majority of systems are developed by means of programming languages: artificially
constructed languages to code the instructions for a computer. These languages have their
own vocabulary, grammar (syntax), constructs and have often been designed to meet the
demands of developing certain types of applications.
Lately, more and more systems are being developed partially or wholly by means of
application generators. An application generator allows the system developer (or even end-
users) to define problems for the computer in terms of inputs, outputs and processing
requirements, without having to specify technical implementation issues such as how to store
data in memory or on file. In theory, these tools require no programming knowledge; in
practice, all but the simplest of applications produced by these generators require a substantial
amount of tweaking: changes made manually, using a programming language, in order to
make the program function properly.
A computer application consists of a series of detailed and unambiguous instructions. When
the CPU executes a program, these instructions must be in machine language: the binary code
that can be interpreted directly by the CPU. As will be shown below, it is extremely difficult
to write even the simplest application directly in binary code. In addition, each different type
of CPU has a different set of programming instructions (also called operation codes or op
codes) which would require you to rewrite your application for each different CPU type. In
practice, almost all applications today are written in a higher-level programming language.
The list of instructions in a programming language is called the source code. A translation
program is then used to translate this source code into the object code i.e. the low- level
machine instructions that can be interpreted by the CPU. There are two basic types of
translation programs.
•
Compilers - programs that translate a high-level language program in its entirety into a
new, machine language program. This program is called the executable or compiled
program. To run the program, the compiled program can be loaded directly by the
operating system into memory and executed as such by the CPU. The original source
code is not needed to run the program; and neither is the compiler. Of course, the source
code will be needed by the developer whenever a change or modification needs to be
made to the application; in which case the application has to be re-compiled.
• Interpreters - programs that convert each of the source program's individual instructions
one at a time into equivalent machine language instructions and execute them before
translating the next instruction. This is done every time the program is executed. Hence
many instructions may have to be translated and executed several times during a single
execution of the program. The source program as well as the interpreter must always be
available whenever the program needs to be executed.
As can be inferred, it is usually much more efficient to compile than to interpret a program. A
Discovering Information Systems 57
5. Software
Section II
compiled program also guards the intellectual property of the developer better, since the users
do not have access to the source code. Most commercial software is being distributed in
compiled format. The advantages of interpreters are their interactivity (especially useful while
developing and debugging the application) as well as the smaller size of the program code. An
example of an interpreted language is old-style BASIC although application macros,
spreadsheets and JAVA virtual machines share many characteristics of interpreters. In
practice, hybrid models have been developed that combine the benefits of both compiler and
interpreter.
With this basic terminology out of the way, let us look at the various types of programming
languages.
5.3.2 First generation: machine language
The lowest level in which programs can be written is machine language (ML). This is the
binary code that can be interpreted directly by the CPU. Obviously, this machine language is
dependent on the type and "model" of CPU the computer is using; since each CPU has a
different instruction set. The instruction set, also called the operand set or op set, is the
collection of different instructions a specific CPU is able to understand and execute.
The following is a code fragment in machine language from the MS-DOS operating system.
(A full listing of just the command interpreter alone would fill this entire book!) Each
sequence of 8 bits is equivalent to a single byte.
00001110
00001100
01000011
00101110
00000001
00011110
00101110
00000001
00000000
11111111
11101000
00001110
11111111
11111011
00011110
00101110
00111001
00101110
00101110
11101000
00001110
00010000
00000000
11111111
Because these sequences of Is and Os are extremely difficult to read, programmers usually use
hexadecimal (or hex) notation, which is actually a shorthand for binary notation. Each
sequence of 4 bits is "collapsed" into (or represented by) a hexadecimal "digit" from 0 to 9,
and A to F as per following table.
Binary
Code
Hex
Code
0000
0
0001
1
0010
2
0011
3
0100
4
0101
5
0110
6
0111
7
Binary
Code
Hex
Code
1000
8
1001
9
1010
A
1011
B
1100
C
1101
D
1110
E
1111
F
Thus the machine language instructions above can be represented much more compactly in
hexadecimal code groups as follows.
0E 2E FF 2E 0C 01 FB E8 43 00 IE 0E
2E FF 2E 10 01 E8 39 00 IE 0E 2E FF
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LOAD
SALES
MULT
2D
IFLT
1000D
JUMP
INFLATE
STOR
BIGSALES
Section II 5. Software
Needless to say, this approach to software development is extremely error-prone and time-
intensive: a single bit out of sequence would halt the program.
5.3.3 Second generation: assembler language
The development of assembler languages represented a big improvement by replacing the
binary or hex code with mnemonics that are easier to remember. Also, instead of having to
track each memory address, so-called symbolic address could be used to give more descriptive
names to memory locations. E.g. instead of referring to memory location "E8 39", one could
call it "SALES".
The following is a sample fragment of assembler language code (with lower-case comments
on the right-hand side).
LABL INFLATE Start of program segment "Inflate"
Retrieve "SALES" value from memory
Multiply it by the (constant) "2"
Check if result is less than "1000"
If so, continue back at "INFLATE"
Else, store the result in BIGSALES"
Although this is a great improvement on machine code, it was still very cumbersome. Hence
the development of third-generation languages.
5.3.4 Third generation procedural languages
Third-generation (3GL) or procedural languages provided a much higher level of abstraction.
Although each 3GL instruction still corresponds more or less directly to a chunk of equivalent
assembler instructions, a lot of the nitty-gritty detail household work is performed by the
compiler. Another advantage of 3GL is that these languages are generally fairly computer-
independent. Each computer manufacturer will develop a language interpreter or compiler for
his own machine, so that the software developer does not have to worry about what
instruction set is supported by any particular CPU.
Many different 3GLs have been developed during the 60s and 70s. Some of the more
successful ones were BASIC ("Beginner's All-Purpose Instruction Code"), COBOL
("COmmon Business Oriented Language"), FORTRAN ("FORmula TRANslation
language"), ALGOL ("ALGOrithmic Language"), PASCAL, LOGO, C, PL-1 and many
more.
The following mini-program in BASIC will draw a sine curve.
SCREEN 2
VIEW (20, 2)-(620, 172), , 1
CONST PI = 3.141592653589*
WINDOW (0, -l.l)-(2 * PI, 1.1)
Style% = &HFF00 ' Use to make dashed line.
DO
PRINT TAB (20) ;
INPUT "Nr of cycles (0 to end) : ", Cycles
CLS
LINE (2 * PI, 0)-(0, 0), , , Style%
' Draw the x (horizontal) axis.
Discovering Information Systems 59
5. Software
Section II
IF Cycles > 0 THEN
' Start at (0,0) and plot the graph:
FOR X = 0 TO 2 * PI STEP .01
Y = SIN (Cycles * X)
' Calculate the y coordinate.
LINE -(X, Y)
' Draw a line from last point to new point.
NEXT X
END IF
LOOP WHILE Cycles > 0
Anyone who has ever written any computer program or been exposed to a 3GL, will be able
to understand many of the instructions above, so the 3GL can be considered much more
programmer-friendly than the earlier generations. But they are still not friendly or natural
enough, definitely not in the eye of non-specialist end-users.
5.3.5 Fourth generation languages and query languages
There is no consensus as to what qualifies a language as a "fourth generation". Some authors
argue that any non-procedural language is fourth generation, others reserve the term "fourth
generation language" (4GL) for database query languages only.
A query language is a high-level language interface provided by database management
systems for accessing data stored in the database. As database management systems are
getting more sophisticated, the query language is becoming increasingly natural. Here is how
one would request a list of the names of all Cape Town customers who bough a Golf costing
more than R40000.
• Using a fairly structured query language:
y TABLE FILE CUSTOMER
y DISPLAY CUST_NAME WHERE (PROD EQ 'GOLF' AND CUST_CITY EQ
'CAPE TOWN' AND PRICE GT '40000')
• Using a Query -by -Example interface:
CUST_
CODE
CUST_
NAME
PROD
PRICE
CUST_CITY
*
GOLF
>40000
CAPE TOWN
• Using a fairly advanced 4GL natural language interface:
y SHOW ME ALL THE CAPE TOWN CUSTOMERS THAT BOUGHT A GOLF
COSTING MORE THAN 40000 RAND
5.3.6 Object-oriented languages
Procedural programming languages still construct a program as a list of instructions. The
computer starts executing instructions at the beginning of the program, processes them more
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Section II 5. Software
or less sequentially, operating on some data set stored on a file or database outside the
program, until the end of the program is reached. Object-oriented (00) languages take a
complete different approach.
Initially, 00 languages were used to simulate physical, real-world systems as studied by the
natural sciences. Lately, it was found that 00 languages were a natural choice for the
development of graphical user-interfaces, distributed environments and very interactive
applications. An early 00 language was Smalltalk but current popular languages are C++ (for
operating systems and end-user applications) and JAVA (for Internet and multiple platform
applications).
The first step in developing an object-oriented application is to identify suitable objects.
These can be physical entities such as an employee or a part; or they could be informational
entities such as an invoice or report. These objects then not only become independent
"holders" of the data pertaining to them, they also encapsulate or contain the methods: actions
or instructions that can be performed on the data. The different data elements of each object
are its attributes. Data is sent to/from an object, or an object is requested to execute a certain
action by means of a message sent to it by another object.
A way to look at an object-oriented application is to view it as a managed "cloud" or
collection of objects, each sending each other messages and executing their activated
methods, in turn generating more messages to other objects etc. Because the execution of the
00 program depends on certain events (e.g. a user clicking on a certain icon, or a "ready"
signal from a hardware device) to trigger other events by means of messages, the 00 model is
often referred to as an event-driven model. Objects sit and wait until they are triggered by
some outside event - usually a message from another event. An object reacts to the trigger or
message by invoking one of its methods, which may update its state (internal data attributes)
and/or send messages to other objects
This can be illustrated by means of an extremely simplified example of whereby a customer
places an order via the Internet on the corporate order system, although nothing would really
change if an internal clerk was processing a telephonic order on-line. The Internet software
would send an order form (a message) to the order processing object (which is really a large
application). The arrival of this form triggers the "process a new order" method. Amongst
other things, this method will send a message with the person's details (a customer object has
attributes such as name, address and credit limit) to the credit-checking object (this may be a
small object containing a tiny verification method, an large in-house application running a
check against the customer database or even an on-line system of an external credit bureau).
The credit-checking object will reply with a message saying whether credit is approved.
Another message will be sent to the "inventory checking object", probably an independent on-
line application running on another computer. This object will check (and possibly hold)
current available stock and reply with an "in stock" or "out-of-stock" message. In the latter
case, it could even contact the information system of a supplier to place a back-order. In the
meanwhile, the order processing object will keep track of incoming messages and re-send
messages if "time-outs" are experienced. Eventually, the customer will be informed of the
order status and, if everything is ok, the order message will be forwarded to the shipping
system (object). As you see from this example, the 00 paradigm is ideally suited to a real-
Discovering Information Systems 61
5. Software
Section II
time, distributed network environment.
5.4 Operating Systems
The PC of a business end-user will quite commonly provide a number of different application
programs, but no program development tools. It is also possible (although unlikely) that the
PC of a programmer could provide development tools only, and no other commercial
applications. But the one thing that all these machines would definitely have is an operating
system (OS). The operating system is an essential piece of software that resides on virtually
every computer. It allows the computer to run a number of different applications apparently
simultaneously, and shares resources such as printers between a number of different users,
while at the same time performing those functions that are critical to the correct operating of
the computer system, regardless of which application is running.
Different types of computers may require different operating systems. Most mainframe
computers have a proprietary operating system, such as IBM's MVS or Siemen's BS2000. At
the opposite end of the market, we find that the leading operating system for the IBM-
compatible Personal Computers is Microsoft Windows (having all but replaced its
predecessor MS-DOS) although Mac-OS and Unix variants such as Linux also have strong
followings.
The Computer User
Sys-
tem
Util-
ities
User Interface
Appli-
cation
#1
Other
OS
functions
Applic
ation 3
Applic
ation 2
Device Drivers
Computer Hardware
CPU, RAM, disk storage, I/O devices...
Figure 5-4: Some operating system components
Today's operating systems are true marvels of engineering and rate among the most complex
artefacts designed by humans. Their complexity stems from the increasing number of
functions that an operating system is required to handle.
5.4.1 Multitasking.
Today's computers handle many applications at the same time: you could be downloading a
file from the Internet at the same time as you update a spreadsheet that is embedded within a
word-processing document (while at the same time your virus scanner is running in the
background). Each application needs to share the CPU, main memory and all peripheral
devices. The OS sees to it that all conflicts are resolved and each application gets a fair share
of the common resources, often in accordance with a certain priority schedule. An important
task, therefore, is that of the proper scheduling of different tasks. The OS also ensures that ill-
behaving applications do not impact on the integrity of the other applications and their data.
(By the way, when a single application program runs multiple tasks simultaneously, this is
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Section II 5. Software
known as multithreading.)
5.4.2 Multi-user management.
Barring the personal computer, computers have more than a single user at any one time - a
typical mainframe may have to handle many thousands of simultaneous users. Each of the
users may operate a different application (see multitasking) but will not be prepared to wait
for other users to finish their tasks. So the OS sees to it that each user gets a fair share of the
CPU of the mainframe, by slicing each second in tiny fractions and allocating them to the
different users. In addition, each user may have a different profile in terms of access to certain
peripheral devices and data. This requires sophisticated security and data management.
5.4.3 Memory management.
Apart from the CPU, primary memory is often the most expensive and scarcest component of
a computer system. Efficient memory management is a key component of any OS, especially
in multitasking and multi-user environment. The likelihood that there is sufficient memory to
load all the data and software for all users simultaneously is extremely small. In practice, a
technique of virtual memory is used whereby the available amount of main memory is
extended by using secondary storage devices, usually the hard disk. During a typical program
execution, not all program instructions and data are required at once. The OS will swap out all
unused software and data segments onto disk, until they are actually required.
5.4.4 Secondary storage management.
All applications require disk storage - if only to store the application software itself. The OS
provides the common access routines to the secondary disk storage devices. It will keep track
of data and program file names, physical locations and perform common functions such as the
copying, erasing or backing up of data. It also makes the differences in physical hardware as
transparent as possible: a data file will appear the same to an application whether the data is
being loaded from a diskette, a hard disk or an optical CD-ROM.
5.4.5 Peripheral handler.
Apart from managing the memory and secondary storage devices, the OS is usually also
responsible for the handling of other peripheral devices. Again, a major objective is to relieve
the application from the responsibility of having to cater for a multitude of different possible
input and output devices. Thanks to the OS, a program (developer) does not need to cater for
the differences between a trackball, mouse or other pointing device. The OS will also ensure
that your document will be printed correctly, regardless of whether you have a colour inkjet, a
laser or lowly dot-matrix printer attached. Equally, individual programs no longer have to
worry about the resolution or capability of your computer monitor. The critical element is
again that the applications do not have to worry about the actual hardware connected to the
computer system. This is usually achieved by means of device drivers, small software
routines that become part of the operating system and help it to interface correctly with
specific hardware devices. The device drivers for popular or standard devices are usually
already included in the operating system More esoteric or very new hardware devices will
come with a separate disk containing the proper device drivers. These then have to be
Discovering Information Systems 63
5. Software Section II
installed as part of the operating system at the same time as connecting the hardware.
5.4.6 Communications Management.
Communications software allows a computer to recognise the presence of other machines on
a network, and to grant or restrict access to local files. It also manages network traffic, by
monitoring communications lines and diagnosing problems, as well as sending and receiving
data to and from remote devices. While PC operating systems include some basic networking
and communications facilities, network operating systems (NOS) such as Novell and Unix
provide sophisticated management tools for large networks.
5.4.7 User interface.
Until the late 1980s, operating systems focussed on the efficient management of resources,
tasks and secondary storage. The popularity of personal computers meant that a whole class
of less-technical end-users entered the world of computing. This pressured the IT industry
into developing a user-friendlier graphical user-interface and the user interface is quickly
becoming a significant part of microcomputer operating systems. Different types of user
interface have already been discussed earlier in this chapter.
5.4.8 System Utilities
As a logical extension of the operating system, additional system utilities are often required to
assist with the proper and optimal use of the computer. Some system utilities may be provided
along with the operating system, while others are marketed by independent third-party
vendors.
A number of system utilities focuses on improving the functionality of the operating system
(e.g. better hard disk management) while others provide additional functions (e.g. anti-virus
or encryption software). More examples of system utilities are editors, additional security
utilities, performance monitors, file viewers, data compression software etc.
5.5 South African Perspective
A simultaneous-translation computer that can be accessed via cellphone to interpret business
conversations between different languages has been developed by a team of German
computer scientists. The Verbmobil uses an innovative speech-analysis process that
recognises how intonation can change the meaning of a sentence, and that can correctly
interpret hesitation or correction signals such as "um" and "er". The development of the
Verbmobil was based on the principle that computers will not become a universal technology
unless the limitations imposed by language differences can be overcome. The prototype
version of the Verbmobil can translate Chinese, English, German and Japanese - in a country
like South Africa, with 11 official languages and a high rate of illiteracy, let's hope that that
the commercial development of this product is not too far away!
5.6 Beyond the Basics
In January 2003, the heads of ICT departments of the South African government unanimously
decided to pursue the deployment of Open Source Software within government. Open Source
64 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 5. Software
Software (OSS) is software that is made available in source code form, at no cost to
developers, who can then create further products derived from the software, as well as
correcting any bugs discovered in the original source code. Examples of OSS include the
Linux operating system, Apache web server, Mozilla browser and StarOffice application
suite.
Members of the Government IT Officers Council commented that the use of OSS would
encourage technological innovation, and would also make it possible to develop systems that
would meet local requirements, by removing the restrictions usually imposed by proprietary
software developers.
5.7 Exercises
5.7.1 User interfaces
For each type of user interface described in this chapter, suggest a business context in which
its use would be appropriate (briefly describe the business activity, typical user and location).
5.7.2 Types of application software
Use the internet or trade journals to identify examples of the following types of applications.
For each example, give the trade name of the product and its distributor, and briefly
summarise its main features.
• Three general purpose (productivity) applications NOT distributed by Microsoft
• Three generic business applications
• Three scientific applications
• Three miscellaneous applications
Discovering Information Systems 65
6. Networks & Telecommunications Section II
6. Networks & Telecommunications
One of the fastest growing technology areas is that of telecommunications (often referred to
as telecoms). Organisations have realised that stand-alone computers present many problems:
fragmentation of data, lack of control, insufficient integration and limited opportunity for
teamwork. One of the major trends over the last decade has been the move not only to have a
personal computer on the desk of virtually every knowledge worker, but to have that
computer linked to the other computers in the organisation.
This chapter deals with the basic telecommunication devices, the types of computer networks
and the telecommunications services available in South Africa. We conclude with a
discussion of arguably the most interesting development in information systems of the last
decade: the Internet.
6. 1 Computer Networks
When a numbers of computers are connected together, they form a computer network. There
are many ways of classifying computer networks.
6.1.1 Networks according to size.
Networks sizes can range from tiny to very large.
(5 Personal Area Network (PAN): consists of two to five computing devices. This not very
common term would apply to the network typically found in the home, and may be based
on wireless technology e.g. Bluetooth..
(5 Local Area Network (LAN): the most common type of network. It consists of from about
four up to as many as a couple of hundred of computers linked together with one set of
cables, usually within the same building. Most LANs are controlled by a central file
server that takes care of network communications, security control and the storage of data
files. A student computer laboratory typically constitutes one LAN.
(5 Metropolitan Area Network (MAN): a network infrastructure linking various local
businesses within a large city area. This is now almost completely superseded by the
Internet.
(5 Wide Area Network (WAN): the opposite of the LAN. It links computers over large
geographical areas. This network usually makes use of the public telecommunications
network. The widely dispersed Automatic Teller Machine (ATM) network of a
commercial bank is typically part of the bank's WAN.
S Value-Added Network (VAN): although not relating to size (but it rhymes with the
others!), it refers to the provision of a network infrastructure service to other businesses.
The service goes beyond the physical cabling and includes "value-added services" such as
limited data and transaction processing or message routing. An example for the banking
industry is the provision of an inter-bank Electronic Funds Transfer (EFT) and clearing
66 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II
6. Networks & Telecommunications
service, linking the computers of different commercial banks (and, possibly, retailers)
together.
6.1.2 Network Topologies.
The network topology refers to the physical and logical way in which the computers in a
network are connected together. Although there are a number of proprietary ways, the
following three are the main topologies in common use (refer Figure 7-1). Note that these
topologies usually refer to a LAN configuration.
G The star network is driven by one central computer to and through which all other
computers communicate. Although this allows for central co-ordination and control, it
requires a very reliable central computer and lots of cables.
£ The ring network consists of a continuous loop connecting all computers. Signals travel
in a given direction and all computers have equal access to the data. A special version of
the ring network is the token ring whereby a special code, the token, is passed around the
ring. This token serves as the data holder and computers can send information only after
grabbing an available i.e. empty token, adding their data and passing the token back onto
the network.
G The bus network is currently the most popular configuration. A central data cable is used,
to which each computer (and other devices such as printers and routers) can be attached.
Although bottlenecks can occur, its popularity stems from its inherent robustness: devices
can be added or removed without affecting the rest of the network. Data clashes (two
computers attempting to send information simultaneously) can prevented by a variety of
means.
rl
jrtL 3r?
r g| netw
A
■
■
Star
network
^ *
Bus network
Figure 6-1: Network topologies
6.2 Telecommunication Devices
Regardless of the network topology that has been implemented, the same basic equipment is
Discovering Information Systems
67
6. Networks & Telecommunications Section II
used to connect the different computers and to ensure error-free data transmission between
them.
•
Network cables are the physical wires by which computers are linked together. The most
common types are:
o Twisted pair: thin insulated copper wires, combined in one single cable. This is similar
to the wire used for voice telephone connections.
o Coaxial cable: (or coax) a thin copper wire inside a tube of insulation material,
surrounded by a sheath or mesh of conducting wire, again insulated on the outside.
This is similar to the wire used to connect antennas to video or TV equipment.
Because there is less possibility of interference, it allows greater volumes of data to be
transmitted in a given time - the amount or volume of data that can be transmitted
over a network connection is referred to as bandwidth.
o Optical fibre or fibre-optic: a translucent and flexible material through which laser
light can travel over long distances. This fibre is much more difficult to work: it
requires special connectors as well as lasers and sensors (with electronics-to-light
converters) at each terminal. Although this technology is more expensive, laser light
can be switched on and off a lot faster than electricity (and it travels ten times faster),
resulting again in a much greater bandwidth.
o Wireless: not all computer devices need a physical cable connection. Because of the
cabling costs and hassles, engineers have explored many methods of transmitting data
without the use of wires. For short distances, infra-red signals work well albeit slowly
- the same technology as your VCR remote control. For longer distances and higher
bandwidths, radio frequencies or other parts of the electro-magnetic spectrum are
used. Satellite technology is increasingly being used for digital data transmissions,
especially in conjunction with Global Positioning Systems (GPS).
Network interface cards (NICs) are necessary when computers are connected directly to
other computers by means of digital network cables (as opposed to the situation when two
computers are connected to each other via a telephone link). Their primary function is to
make sure that there are no transmission conflicts with the other computers linked to the
network, since data may be simultaneously sent and received by many different
computers all linked to the same network. In addition, the network card usually fulfils an
error-checking function, to ensure that uncorrupted data is received at its destination.
Multiplexers allow a single channel to carry data transmissions simultaneously from many
sources, by merging them at one end of the channel and then separating the individual
transmissions at the receiving end of the channel.
Front-end processors (FEP) are used in bigger networks that are centrally controlled by
large computers - often mainframes. In order to give the expensive mainframe more
"time" to concentrate on application processing, it needs to be relieved from the rather
mundane task of network control. FEPs handle all or most communication processing
such as error-checking, data conversion, packaging and transmission control.
68 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
•
•
Section II 6. Networks & Telecommunications
• Routers and bridges are computers dedicated to the translation of network protocols and
standards between different networks. They are becoming important as more and more
organisations are linking their own networks to those of other organisations. They may be
using
o different operating systems (Novell, Unix or Windows NT),
o other technologies (coax or fibre-optic),
o or different protocols (proprietary or public standards set for computer
communications).
• Finally, the modem allows a computer to communicate
with another computer by means of the public voice
telephone network, rather than by using digital
cabling. This requires the conversion of digital computer
signals (used inside the computer) into analogue sound signals
(that can travel over the voice telephone lines) - this process is called modulation. At the
other end of the line, these sound signals are converted back into digital signals - or de-
modulated. The word modem refers to this modulation / demodulation process. You may
have heard this "modulated signal" when listening to a fax machine, which is really a
scanner/printer/modem in one. Since the modem replaces the network card, it usually
carries out similar error-checking functions to ensure the correct transmission of data.
Trivial fact: More than 5000 satellites are orbiting the earth and most of them are involved in
telecommunications.
6.3 SA Public Telecommunications Services
Because telecommunication services are a critical part of any country's infrastructure, most
governments have been very protective towards their telecoms. Paradoxically, this
protectionism often resulted in high tariffs (monopolies!), thus reducing the overall
competitiveness of local businesses. Recently more and more countries have started to
privatise these services and allowed competition to drive prices down. The South African
public telecommunication services are controlled by Telkom, although its legal monopoly is
being phased out. The following are the main data network services provided by Telkom
6.3.1 Public Switched Telephone Network (PSTN) Services
The oldest data service provided by Telkom is the Datel service, which provides a connection
between computers by means of the standard Public Switched Telephone Network (PSTN) i.e.
the same as the normal voice telephone traffic. This requires the use of built-in or external
modem equipment that modulates the digital signal into an analogue audio signal (and de-
modulates it back at the receiving end). This service is quick and easy to set up since it is
available anywhere where there is an ordinary voice telephone point. The main drawbacks are
the limited transmission speed, high error rate and the lack of security. Customers may choose
between a dial-up or leased line connection.
Discovering Information Systems 69
6. Networks & Telecommunications Section II
6.3.2 Diginet
Diginet is a dedicated digital data service from Telkom that provides reliable and efficient
point-to-point (i.e. not switched) data connections. It differs from the Datel network in that
the transmission path is entirely digital: a combination of fibre-optic, microwave and coaxial
cable. Because the signal does not have to be translated into analogue form, no modem is
required, resulting in a cost saving. However, its main advantages are the higher transmission
rates and a substantial reduction in transmission errors. The standard Diginet service allows
for 64 kpbs (kilobits per second) though an enhanced service called Diginet-Plus has been
designed to transfer up to 1920 kpbs, which allows slow-scan TV and video conferencing
signals to be transmitted in real-time.
6.3.3 Public Switched Data Network (PSDN) Services
Saponet is Telkom' s Public Switched Data Network (PSDN). The Saponet-P service relies on
a packet-switching mechanism whereby all data transmissions are broken up into smaller,
standard-size units or data packets. Each of these packets is then routed independently to their
destination. The path travelled by the packet depends on the available capacity and
bottlenecks. At the destination, the original transmission is reassembled out of the constituent
packets. A Packet Assembler & Disassembler (PAD) is responsible for the breaking up of a
message into packets and the opposite process of reassembling packets into a message at the
destination. This PAD can be a separate hardware device or a software program.
6.3.4 X.400 and Telkom400
Telkom400 is a VAN on top of the X.400 infrastructure. It supports electronic message
handling and electronic data interchange (EDI). EDI is the automated computer to computer
application exchange of structured business data between different organisations. An
international standard defines common business documents such as order forms, invoices or
electronic funds transfer documents that are exchanged directly between the computers of the
respective business partners.
6.3.5 ISDN and ADSL
Now that most of Telkom' s telephone exchanges have become digital, Telkom is able to
provide new functions and services. One all-digital connection that has sufficient capacity
(bandwidth) to support speech, video conferencing, facsimile, data and image transfer. This
connection is called an ISDN line (Integrated Services Digital Network) and is currently
available in selected metropolitan areas. Much more popular is the newer Asymmetric Digital
Subscriber Line (ADSL) which allows a broadband connection (at least several hundred
kilobits/second) over your standard telephone line while keeping the line available for voice
telephone calls. It is called "asymmetrical" because the standard allows for much greater
"download" than "upload" speeds; this reflects the typical home user pattern. Higher volumes
and transmission speeds of up to 150mbs - typically needed by mid-size and larger businesses
- are available through Telkom' s ATM Express service.
6.4 The Internet
The Internet is probably the most exciting, the most popular, most visible and definitely the
70 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 6. Networks & Telecommunications
"coolest" information systems development of the decade.
6.4.1 What is the Internet?
The origins of the Internet can be found in the early sixties, when the US Department of
Defence sponsored a project to develop a telecommunications network that would survive a
nuclear attack. It had to link together a diverse set of computers and work in a decentralised
manner so that, if any part of the network were not functioning, network traffic would
automatically be re-routed via other network nodes. This project quickly grew into a popular
academic network linking virtually all major research institutions and US universities. Soon
other countries jumped onto the bandwagon, thus linking academics and researchers across
the globe. True to the academic ethos, it quickly became a means for global information
sharing. By now, businesses also got a piece of the action. This was spurred on by the trend
to network the personal computers in home and business environments and the development
of more user-friendly, graphical interfaces: the web-browser and the Windows operating
system.
The Internet (or, more colloquially, the Net) consists of a huge and fast-growing number
(hundreds of thousands) of interconnected wefworks linked together. Currently more than 100
million users are connected to the Internet. The popularity of the Internet can be explained by
the amount of information it makes available: the equivalent of many libraries of information
is stored on millions of computers {Internet hosts), much of it free of charge to all Internet
users. This information is provided by educational institutions, governmental agencies and
organisations, individuals, and increasingly by businesses. Hence, the Internet is frequently
referred to as the Information Highway or the Infobahn.
But the Internet is more than just a huge information resource. Its initial purpose was to act as
a communications network and it fulfils that role well. It is the transport mechanism for
electronic mail, the transfer of computer files, remote computer access and even allows for
voice calls. Businesses quickly realised the potential of the multimedia-enabled Internet for
marketing purposes. Of late, more and more business transactions are being conducted via the
Internet: electronic commerce (e-commerce) is the latest revolution to be embraced by the
Internet community.
6.4.2 Electronic mail
Probably the most popular Internet service is electronic mail, more commonly known as e-
mail. This consists of the sending of messages composed on the computer, via a network,
directly to the computer of the recipient who reads the message on his/her computer.
Knowledge workers with access to e-mail write five to ten times as many e-mail messages as
hand- written notes. The following are just some of the advantages of e-mail.
• Reliability: although there is no guarantee, you will normally receive quick feedback
if the address does not exist or there is a similar delivery problem.
• Efficiency: many short-cut tools exist to increase your efficiency when composing
messages. You can use your computer's cut-and-paste function, you can have
managed address books and lists, when replying to another message you can
automatically incorporate any part of the message to which you are, etc. And it is just
Discovering Information Systems 71
6. Networks & Telecommunications Section II
as easy to send a message to one as to a whole list of addressees. (Admittedly, this
results in a lot of abuse and information overload on the recipient's side.)
• Digital: e-mail is composed on a computer and remains in computer-readable format
all the way to its destination. Thus one can also easily incorporate other computer data
such as graphics or document files.
• Cheap: because the capacity of the Internet and disk storage is increasing all the time,
the cost of a sending and storing a one-page e-mail message is negligible.
• Speed: messages are generally delivered across the world in a matter of seconds.
The e-mail address
Just like with ordinary postal mail (now usually referred to as snail-mail), you need to know
the recipient's address before you can send your message. Internet e-mail addresses have a
standard format: username@ domain. The username is often the name that your addressee
uses to connect to the network, e.g. "jvanbelle" or sometimes a long number. This username
is allocated by the LAN administrator. The domain identifies the file server, which acts as the
local post office for your recipient's e-mail. The domain consists of several parts, separated
by full stops or dots. The international standard for domain identification is <name of LAN
server>.<name of organisation>.<type of organisation>.<country code>.
• The country code is the international two-letter code for the country e.g. qu for
Australia, za for South Africa, sa for Saudi- Arabia, uk for Great Britain, etc.
• The two most common types of organisations are co for a commercial organisation
and qc for an academic institution . Less frequent are org for (not-for-profit)
organisations, mil for military, net for networks and gov for government agencies.
• Each country has a national Internet naming body that allows its organisations to
chose their own name, as long as no one has claimed the same name before.
Examples of South African domain names are anc.org.za, uct.ac.za, fnb.co.za.
• Large organisations often refine the domain further by adding the name of their LAN
servers, e.g mail.uct.ac.za.
Examples of possible e-mail addresses are: JaneDoe@stats.uct.ac.za (Jane working in the
statistics department at the University of Cape Town in South Africa); info@ anc.org.za
(information department at the ANC, a political party) or SoapJoe@marketing.bt.co.uk (Joe
Soap in the marketing department of British Telekom in the U.K.).
The US Americans, having "invented" the Internet, use a slightly different way for their
addresses. They leave off their country code (us) and use com for commercial organisation or
edu for educational institution. Since the majority of Internet users hail from the US, you will
encounter many addresses such as JWood@mit.edu or Bill@microsoft.com.
Netiquette
Just as in any other social interaction environment, there are some rules and guidelines for
appropriate social behaviour on the Net: Netiquette (etiquette on the Internet). The following
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Section II
6. Networks & Telecommunications
-)
Happy face
-(
Sad or sorrow
-)
Wink
-0
Shock
-\
Sarcasm
Al
Wide grin
-X
Blowing a kiss
'(
Teary-eyed
-P
Sticking tongue out
8-)=
Beard & glasses
:--)%
Boy on skateboard
<g>
Grin
<w>
Whisper
(U!
Hntr von
are some illustrative examples pertaining primarily to e-mail.
• Shouting^ THE PRACTICE OF TYPING ENTIRE SENTENCES IN UPPER CASE is
generally seen as novice (newbie) behaviour and frowned upon. Perhaps it stems from the
disgust with old teletypes and mainframe terminals that did not have lower-case
characters.
• The use of emoticons to indicate emotive content of a
sentence is highly recommended. Typed text does not
reveal any body language and a joking remark can easily
be interpreted the wrong way. Whenever one writes
something in jest or with humorous intent, it is advisable
to add an emoticon. An emoticon (an icon indicating
emotional content) consists of a series of text characters
which are meant to be rotated a quarter turn and represent
a laughing:-) (i.e. equivalent to J or the smiley) winking
;-) or sad face :-( L .
Flaming is the carrying on of a heated
personal emotional debate between two or
more individuals on a public Internet forum. A
flame war is generally a sign of immature
behaviour by individuals who cannot take
perspective and should really take the
discussion off-line.
Netizens (inhabitants of the Internet i.e.
frequent net surfers) often use standard but, to
the non-initiated, cryptic abbreviations. Examples are: BTW = by the way ; ROFL =
rolling on the floor with laughter ; TPTB = the powers that be ; BRB = Be Right Back.
This vocabulary has been adopted and expanded with the growth of Short Message
Service (SMS) use on cellular phones.
6.4.3 The Web
The Internet service that has received the most attention from the public media is the World-
Wide Web or the Web for short (sometimes also called IVWW or W3). The Web is a vast
collection of multimedia information located on Web servers attached to the Internet.
Its popularity is due to a number of reasons.
• Information links are transparent. Links to any other piece of information located
anywhere on the Internet can be inserted in a web document. A simple click of the mouse
takes the reader completely automatically from one Web server to another, quite possibly
in another country.
• Information can be presented in a hypertext link format whereby one can jump
immediately from one concept to a related concept or explanation. No need to read text in
BTW
By the way
IMHO
In my humble opinion
FWIW
For what it's worth
SO
Significant other (partner)
BRB
Be right back
FAQ
Frequently Asked Questions
RTFM
Read the f*** manual
TTYL
Talk to you later
IRL
In real life
F2F
Face to face
LOL
Laughing out loud
Discovering Information Systems
73
6. Networks & Telecommunications Section II
the traditional top-to-bottom sequential way.
• It allows for multimedia information. A Web document can incorporate rich and colourful
graphics, animation, video clips, sound etc. Just think of the marketing opportunities!
• The Web supports interactive applications. Web applications can request information
from visiting users and documents can include programming instructions. Users can even
download small programs (often written in Java) that could perform some processing on
the user's computer or display special visual effects.
Reading or accessing information on the Web is called surfing the Net because one jumps
from one hypertext link to another following whatever takes your fancy. In order to surf the
Net you need some special browser program that understands the Web protocols and formats
and presents the information to suit your computer monitor. You also need an access point or
connection to the Internet. Your Internet connection may be automatic if your computer is
connected to a (corporate) LAN that connects directly to the Internet, or it may be by means
of a special subscription to a business that specialises in providing Internet access for others:
the Internet Service Provider (ISP). Access to the ISP for individual users is usually via a
dial-up connection i.e. using a modem and telephone.
Once a newbie (new user) is connected to the Internet (online), she faces the daunting task of
finding her way amongst the huge variety of information offered. The easiest way in is
usually by means of a search engine: a Web site that tries to catalogue the information
available on the Internet. By entering one or more search words, the engine will provide you
with a couple of adverts and a list of documents that contain the word(s) for which you are
looking.
All information on the Web is uniquely identified by the URL (Uniform Resource Location),
which is really the full Internet address of a Web document. The URL consists again of the
Web server's domain address, followed by the access path and file name on the server.
Examples of URLs are www.hotbot.com/sports/main.html (the main page on the sports
section of the HotBot search engine) or http ://www. commerce. uct . ac . za/inf or mationsystems/
(containing details about UCT's department of information systems). Note the similarities
and differences between an URL and an e-mail address.
6.4.4 Other Internet services
A number of other services are available on the Internet. The Usenet consists of ongoing
discussion fora (or newsgroups) on an extremely wide variety of topics, from forensic
psychology to Douglas Adams, from Star Trek to cryptography. The discussion happens
entirely by means of e-mail and, when you subscribe to a given newsgroup, you can browse
through the contributions of the last few days and reply with your own contribution.
More specialised services exist, such as ftp (file transfer protocol) for the transfer of large
computer files, and telnet, the remote access of computers elsewhere, but they are used less
frequently. In any way, these services are now being performed transparently by most Web
browsers. Similarly, older services such as Gopher and Veronica have really been replaced
almost entirely by the Web.
74 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 6. Networks & Telecommunications
6.4.5 Internet protocols and standards
Different computers and networks can communicate via the Internet because a number of
basic Internet communication standards have been defined. Any network connected to the
Internet will translate its own standards and protocols into those used on the Internet by
means of a bridge.
The most fundamental and "lowest level" protocol is the TCP/IP (Transmission Control
Protocol/Internet Protocol). This protocol is also the native protocol of computers using the
Unix operating system, which explains why Unix computers are so popular as Internet
servers.
On top of TCP/IP are the "mid-level" protocols defined for the various Internet services.
Perhaps the best known of these is http (Hypertext Transmission Protocol), which specifies
how the Web information is made available and transmitted across the Internet. Other
protocols and standards are STMP and MIME (for e-mail) or ftp.
Information made available via the Web is usually formatted using a special standard: the
Hypertext Markup Language (HTML), which actually consists of plain text files with visual
formatting commands inserted between the text. Most desktop productivity software allows
you to save your document directly in the HTML format. Special HTML editors allow much
finer control over the final layout of your Web document. A later development is Extensible
Markup Language (XML), which increases the flexibility of web documents by allowing
them to be viewed not only using a web browser, but also on different platforms such as a
PDA or cellular telephone.
6.5 South African Perspective
The internet is being used in South Africa to help in the prevention of child abuse. Ordinary
citizens who are outraged by the high levels of child abuse and wish to make a positive
contribution towards combating and preventing the problem, can now volunteer their
assistance. A website has been launched at www.volunteerchildnetworkorg.za, which offers
volunteers the opportunity to identify the skills they have that could be useful to
organisations, and to connect them with organisations that need their assistance.
A similar type of business operating in Gauteng gives tourists the opportunity for hands-on
work in wildlife conservation, by placing volunteers with various rehabilitation centres,
conservancies and nature reserves.
6.6 Beyond the Basics
Your cellphone may be all you need to gain entry to World Cup 2006 soccer matches. Two
Austrian companies have combined their expertise to develop a paperless ticket system which
allows users to pay for tickets via the Internet, and a few seconds later receive an encrypted
entry code via SMS to their cellphone. The user then gains access to the event by passing the
display of the cellphone, containing the encrypted code, over a special scanning device at the
entry gate.
In order to allow for the various standards of different cellphone manufacturers, users must
Discovering Information Systems 75
6. Networks & Telecommunications Section II
enter the name of their cellphone model when ordering tickets. The developers claim that
95% of all existing handsets are able to use their system. So far it has been successfully tested
at the Football Expo 2002 in Cannes, and at a nightclub in Austria. However, they don't say
what will happen if your cellphone is stolen, or if you accidentally erase that vital SMS !
6.7 Exercises
6.7.1 Search Engines
• The Internet is vast and information is usually located using search engines such as
Google, Yahoo!, Lycos, WebCrawler or Ananzi. Give the name and URL of two other
Internet search engines, of which at least one must be South African.
• Take your date of birth ("DOB") and search the Internet to see if you can find a home
(personal) page of another person who shares your date of birth, or a page reporting on an
event that happened on your DOB. Give the URL of the home page that you have
located, as well as the name of the search engine you used.
• Think of your favourite hobby or sport. Locate a web-site in South Africa (use
www.ananzi.co.za) that is devoted to your interest and give the name of your sport/hobby
and the URL of the main (index) page of the site you have found.
• Go to Independent On-Line (www.iol.co.za). Search the site for the most recent article
that mentions your place of birth and give the full TITLE and date of the article. [If your
birth place is not found, search for the nearest big town to your place of birth.]
6.7.2 Cellular communications
In South Africa, more people have cellphones than have access to computers. What
implications does this have for the development of our telecommunications infrastructure? Do
you think this will have any significant impact in reducing the "digital divide" and improving
access to local and global information resources?
76 [Free reproduction for educational use granted] © Van Belle, Eccles & Nash
Section II 7. Databases
7. Databases
Often one hears about the purchase of a company with few physical assets for large sums of
money. Why are investors often prepared to pay an enormous premium over the asset value of
a company instead of just buying the same fixed assets and starting up a competing company
themselves? There are three main reasons: companies may have extremely efficient business
processes, they may have valuable intangible property such as patents or trademarks, or they
may have a very valuable information database of customers. Company executives are
increasingly realising the value of the information that is contained in the databases of their
information systems. This chapter explores the database component of information systems in
more detail.
7. 1 From File-based Systems to the Database Approach
7.1.1 The File-based Approach
Many small (personal computer) applications, as well as a large number of larger legacy (i.e.
older) corporate information systems take a file-based approach to data storage. The function-
oriented information system stores all its data into its own files. The structure and integrity of
these files is maintained within the application.
As a typical example of the file-based approach, let us take a look at the information systems
of a commercial bank whose identity shall remain anonymous. The bank has developed a
sophisticated system to process its cheque accounts. This system maintains, inter alia, its own
customer information. The bank has another, entirely separate system for its credit card
accounts. This system obviously also keeps customer details in its own files. There are other,
stand-alone systems for mortgage bonds, savings accounts, notice deposits etc. Each of these
systems was developed independently and probably even runs on different computer systems.
None of the information is shared between the applications. What are the problems?
Imagine the typical scenario of a bank customer who moves house. She notifies the bank's
help desk of her change of address, and the next month (with luck) her cheque account
statement arrives at the new address. However, the savings account statement is still sent to
the old address. On enquiry, she is told that the bank was unaware of the fact that she also had
savings account and changed only her information on the cheque system; so now they have to
enter the change of address separately on the savings account system. Surprise! The next
month, her mortgage bond statement is still sent to the old address . . . This is, however, not
the only problem. Imagine what would happen if the customer accidentally issues a cheque
for an amount exceeding her overdraft. A bank clerk bounces the cheque, resulting in an
embarrassed customer, only to discover later that this customer has in fact a large amount
invested in various deposit accounts. The irate customer may well decide to change bank and
the bank loses a profitable customer! In addition, the bank probably loses many marketing
opportunities (such as cross-selling) by its inability to identify multiple account-holding
customers.
7.1.2 The Database Approach
What is the solution? The database approach. All customer information should reside
Discovering Information Systems 77
7. Databases Section II
centrally in one database, and only account-specific information should be stored separately.
All the system applications that require customer information should access the same
customer database. In fact, no individual application will be allowed to access this database
directly. A spcialised system, the database management system (DBMS), will control all
access to the database and be responsible for security, integrity, data formats, backups and
other technical issues. Any application requiring or updating data sends a request to the
DBMS, which will then extract data from, or update, the database.
7.1.3 Advantages and Disadvantages of the Database Approach
The database approach has some disadvantages:
• It introduces an additional layer of software between the application and the database,
often resulting in a slower access to the data.
• System designers and functional users loose some freedom and control over their data,
since they can no longer decide exactly what and how data will be stored. All changes
or additions to the database have to be cleared by the Database Administrator (DBA).
• The reliance on one single database increases the vulnerability of the organisation: the
lack of redundancy, industrial espionage, a higher level of complexity and size.
• A DBMS introduces additional costs: a typical DBMS licence is very expensive and
requires specialised, highly-paid staff.
On the other hand, the benefits of the DBMS usually outweigh the disadvantages by far.
• The performance penalty exists only if a file-based application is extremely well
designed. In most cases, the designers of a DBMS have done a lot of research and
spent much time in optimising the data access routines. As an example: sorting of data
using a very non-intuitive but highly effective method is often hundreds of times
faster than the obvious ways generally adopted by the non-specialist application
designer.
• The centralisation of data facilitates risk management: it is much easier to back-up,
monitor or audit one central database than thousands of separate files.
• The database is independent of the individual applications. The DBA can easily say,
add a new field (or change an existing field) in the database without affecting the
applications. Where the same file was accessed or shared by different applications,
each application had to be individually modified to accommodate a change in file
layout. When the database structure changes, this will generally not affect the DBMS
calls programmed into the existing applications.
• The integration of data in a single logical DBMS view (although it may physically be
stored in many different databases) allows for better management decision support. It
is now possible to have the complete picture or profile of a customer; or to relate
employee performance to sales.
• There is no more, or much more controlled, data redundancy and hence data should be
more consistent.
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Section II 7. Databases
• A DBMS offers many additional tools to access and manipulate the data. It will
typically include powerful security features, backup and disaster recovery tools,
database programming and query language interfaces.
• It is usually easier to upgrade or adopt new technologies. When the DBMS vendor
upgrades the DBMS to include the new developments, these become available
automatically to all applications without major redevelopment efforts. Thus an
organisation may be able to implement object-orientation, e-commerce, client/server
or enterprise-wide systems without costly system conversions.
7.2 Data Structures
In chapter 2, we saw that the smallest data element is the bit: a yes/no, true/false or any
possible choice between two options. We also found that, in practice, a character is really the
smallest practical data element: a character can be a letter, digit or punctuation symbol. Most
textual and numerical data can be represented using characters. However, there are larger
units or groupings of data.
Business information systems currently deal mostly with large amounts of structured textual
(and numerical) data: customers have a name, address, account balance, and place orders that
in turn again contain standard elements such as order date, product item descriptions and
amounts etc. The efficiency of storing and retrieving this data can be increased by structuring
it into a standard format and grouping similar data items together.
7.2.1 Database.
The totality of the data collected by an information system is called the database. Although
the ideal is to have a single database for the entire organisation, in practice organisations may
have a number of functional databases that may not be entirely compatible. The customer
order system may have a database of customers, orders and shipments while the human
resources system may have a completely separate database with employee information, job
positions, training and salaries.
7.2.2 Table and file
Normally, the database will be structured into smaller logical or physical units: tables or files
respectively. E.g. the order database may use one file to keep customer information, another
to keep track of orders, yet another with account details and probably a file with product
details. As we will see later, the table is really a logical concept applicable mainly to the
popular network and relational databases. The file is a physical way in which data is stored on
the computer.
7.2.3 Record
Within a table (or file), information will be organised in the form of records. Each record
represents one instance of a real-world entity or transaction. E.g. in the customer database,
there may be a record containing all the data about Joe Smith (including his address, contact
numbers, credit status), there will be another record with the data for Jane Doe and so on, one
record for each of the customers.
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7. Databases Section II
7.2.4 Field
The information within a record is structured into separate fields. In the above example, Joe
Smith's record would have at least four fields: his name, his address, his contact telephone
number and his credit status. In practice, his name may be split into at least three separate
fields: one for his surname "Smith", one for his first name "Joe", one for his designation "Mr"
and probably one for his initial(s). Similarly, the address will usually be split into several
fields to separate e.g. the postal code, the town and the street. This separation will make it
easier to extract subsets of the data, such as all the sales for a given area, or to print out
customer address labels sorted according to postal code.
7.2.5 Characters and Bytes
Finally, the data inside a field will be encoded in a number of characters (for textual data) or
bytes (for numerical and multimedia data).
When designing information systems, a lot of attention must usually be given to the logical
design of the database. As an illustration, we will look at some of the considerations involved
with fields.
7.2.6 Some Field Design Considerations
Fields can have a fixed length (such as the postal code) or a variable length (such as general
text comments, or a sound track in a multimedia database). Because fixed length fields are
much easier to work with from a technical perspective, system designers often will try to
impose a fixed length on fields that are really variable length fields. E.g. the information
system will reserve 30 characters of space for the "city" address field. Shorter names such as
"Cape Town" will then automatically be "padded" with extra empty spaces (resulting in some
wasted database storage space), but the simpler design (resulting in performance
improvements) will usually offset the marginal cost increase. On the other hand, a problem
results when a city name exceeds the sample 30 characters space limit. To take an extreme
case: not many information systems will cope with the place called "Taumatawhakatangi-
hangakoauauotamateaturipukakapikimaungahoronukupokaiwhenuakitanatahu" in New
Zealand, or, to take a slightly less extreme example, one of the authors often has problems
fitting his first names "Jean-Paul Willy Georges Dominique" on standard forms!
Another problem is often to identify uniquely each record. How would one identify a
customer record? A first thought is to use the name of the customer. However, any large
organisation is likely to have several customers with the same name: in Cape Town alone
there are more than 5000 persons with the surname Abrahams or Smith (and, contrary to
popular belief, only about half as many Mohammeds or van der Merwes). A common solution
is to look for some guaranteed unique field such as an identity number, a combination of
fields (e.g. name and date of birth or address) or by artificially generating a unique code for
each customer: the dreaded "customer code" (or, in the case of student records: your student
number). The field that uniquely identifies a record is called the primary key field and is very
important in database design, not only when searching for a record, but also to link one data
table to another (e.g. when linking customers to their orders).
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Section II 7. Databases
7.3 Database Models
Just as computer hardware and software development languages have seen different
technological generations, database and DBMS technology have also undergone major
changes. This manifests itself primarily in the conceptual database model i.e. the type and
nature of the relationships that are allowed between different data tables.
7.3.1 The Hierarchical Data Model.
The hierarchical data(base) model is the oldest and conceptually simplest model. This
structure allows only for one type of relationship, the "parent-child" (or one-to-many)
relationship. In addition, there can be only one single relationship between tables. This
structure can also be visualised or represented using the image of a tree.
For instance, a customer (the "parent" entity or root) can place one or several orders (=
"child"). Each order, in turn, will consist of one or several line items (the different products or
services that are ordered). In this model, it is very simple to trace the various orders placed by
a customer. However, it is more difficult to investigate the correlation between, e.g. the sales
of different products (line items) according to geographical area (address of customer) or
sales person.
7.3.2 The Network Model
The network data model accommodates the "many-to-many" relationships often found in the
real world. It allows the explicit linking of sets of entities by means of network relationships.
In a university environment, the relationships between courses and students could not (or with
great difficulty) be accommodated in a hierarchical database. Each student can enrol for one
or several courses, whilst each course will have an enrolment of zero, one or, hopefully, many
students. Student Xannie Du Toit may enrol in the 3 courses Quantitative Philosophy,
Exobiology and Data Warehousing; the course Exobiology may have students Jim Mbeki,
Xannie Du Toit, Yusuf Arafat and Wang Ching.
However, although the network model allows more complex relationships to be defined than
the hierarchical model, it is significantly more complicated than the other models to design
and maintain.
7.3.3 The Relational Model
The relational data model, pioneered by Codd, is founded on a sound logical set-theoretical
basis. Although it took well over a decade for his ideas to find widespread acceptance, almost
all major DBMS in use today support the relational model almost in its entirety. Although a
detailed discussion of the relational model is outside the scope of this course, a simplified
example below will illustrate some of the basic concepts and features for a partial university
administration system.
The relational model requires that all data is stored in data tables, with unique key fields (the
primary key) and all other data fields in the table entirely and fully dependent on the key
fields. In the example below, there are a large number of tables (the relational model tends to
Discovering Information Systems 81
7. Databases Section II
generate a large number of tables). The student table has the student number as the key field.
The order or sequence of individual records is of no concern. Students do not have to be
stored in alphabetical or any other specific order, though they may be sorted for reporting
purposes.
Tables can be linked, by reference to their primary key fields, in any possible way. Links
between tables do not have to be predefined when the database is designed, providing
structural flexibility and efficient information retrieval. Each link between tables is a
relationship and consists of a separate table; e.g. the course enrolment table is really the
"enrolment" relationship. There could be other relationships between the same two tables, e.g.
a "tutor" relationship whereby some postgraduate students have been appointed as tutors for
certain undergraduate course.
The inclusion of a primary key field from another table is called a foreign key. E.g. the
current degree code in the student table is an example of a foreign key. (This model assumes
that an active student can be enrolled for only one single degree.)
Normalisation is a step-by-step process of ensuring that a database structure conforms to the
requirements of the standard relational database models. One might be tempted to include
course prerequisites in the course table by means of a course prerequisite field. However,
some courses may have more than one prerequisite (e.g. Econometrics could require Statistics
1A and Macro-economics 2 as prerequisites). This would require two or more course
prerequisite fields. The latter contradicts the first normalisation rule - no repeating fields are
allowed.
A typical example to illustrate the use of a relational database is that of student enrolments at
the university. There will be a student table containing the student number (the key field),
surname, name, year of first registration, activity status (currently registered or not) and
current degree code (foreign key). Similarly, there will be a course table which contains
course codes (key field), course names, level of course (1st year, 2nd year etc.), type of course
(first semester, second semester, full-year, summer term), responsible department (code),
number of credits, etc. There will be many other "primary" or entity tables such as lecturers,
venues, lecture and tutorial groups etc. The power of the relational model is that it allows any
type of relationship. E.g. in a small university, different students could be assigned individual
tutors, who are senior students, for the various courses. This assignment (in effect, a
relationship) could be stored in a "tutor assignment table" containing at least the following
fields "tutored student" (foreign key = student number), "tutor" (foreign key = student
number), "tutored course" (foreign key = course code). This would be very difficult to
achieve in the network model. Note that it is quite possible, indeed very likely, that there will
be many relationship tables with exactly the same fields (e.g. "students enrolled in course"
and "tutors assigned to course"; or "required courses for degree" and "optional courses for
degree").
7.3.4 The Object-Oriented Model
The object-oriented (00) approach was introduced in the chapter on software. Remember
that an object encapsulates both the data and the methods or operations that can be performed
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Section II
7. Databases
on the data. Although business databases were not initially considered to be good candidates
for 00, more and more applications are benefiting from the use of object-oriented database
management systems (OODMBS).
Two particular strengths of the 00 model are the capability to handle multimedia more easily
and the feature of inheritance. Multimedia, such as pictures or sound, are more easily handled
by OODBMS because it is much easier to store the methods, or procedures, to access and edit
the data within the object than it is to include those methods permanently as part of the
DBMS. As such, OODBMS are popular for engineering and scientific applications. However,
product and human resource databases can equally benefit from picture and photograph fields.
The other advantage is that the 00 model allows specialised objects to inherit object
attributes and methods from their parent. A banking example can illustrate this. A generic
"bank account" object would have the attributes of "owner details", "account number",
"balance", "interest" etc. Specific types of accounts, such as home loans, cheque and saving
accounts, inherit the common account attributes and methods. In addition, each account type
would have its own specific attributes and methods.
BANK ACCOUNT OBJECT
Attributes
ft Balance
ft Interest Rate
ft Customer name(s)
ft Branch
ft Account number ...
Operations / Methods
ft Make a deposit
ft Do a withdrawal
ft Get customer details
INHERITANCE
of attributes and
methods
HOME LOAN ACCOUNT
CHEQUE ACCOUNT
OBJECT
OBJECT
Attributes
Attributes
ft Mortgage property details
ft Overdraft limit
ft Term of account in years
ft Charge schedule
ft Statement details
ft Last cheque number used
ft Insurance premium (Rand)
ft Statement details
Operations / Methods
Operations / Methods
ft Print annual statement
ft Print monthly statement
ft Allocate insurance
ft Calculate credit & debit
premium, interest charges
interest, cheque charges
ft Calculate new monthly
ft Order new chequebook
payment
7.3.5 Free-form databases
Another attempt to deal with unstructured data and information is the free-form database.
Textual (and sometimes multimedia) information can be entered in logical chunks and related
to other pieces of information, often using hypertext principles. These databases feature
powerful indexing and searching tools. Most free-form databases are stand-alone end-user
Discovering Information Systems
83
7. Databases Section II
applications but, in a way, one could consider the entire web to be one huge distributed free-
form database. A free-form database differs from a knowledge-based database in that the
latter must be able to interpret the knowledge to allow for limited reasoning, inference,
specialisation or inheritance.
7.4 Database management
In order for a database to provide and secure efficient data storage and retrieval, there must be
careful control of what data is to be included and how it will be maintained, who has access to
the database, and how errors can best be prevented or resolved.
Normally, a specialist job function will be created for a Database Administrator (DBA), the
person who is responsible for looking after the computerised corporate database(s). The main
responsibility of this person is to define the standard data elements and structure of the
database (i.e. table and field structure). She will also look after the integrity and safety of the
contents of the database, and may be responsible for the maintenance and fine-tuning of the
DBMS software.
An important component of the DBMS is the data dictionary or data encyclopaedia. This
describes in detail all data elements in the database, i.e. all data tables, field names (and
synonyms or aliases), descriptions/definitions, field types (text, numeric values, monetary
units, boolean, dates), field lengths, key fields, relationships and dependencies between fields
and tables, etc.
The database approach distinguishes a number of different views or perspectives of the
organisational data.
G The physical view (or data description) of the data is concerned with where and how
files, tables and records are stored. A large database may be split or distributed physically
over different computers or storage devices; what may seem to be fields of the same
record may actually be stored separately; often used records or fields may be stored
differently to less frequently used data; various different indexing methods may be used
to assist in locating records more quickly etc. The physical data view is the concern of the
DBMS (and the DBA) only.
(S The logical data view or conceptual schema represents the conceptual structure of the
data, as seen from an organisation- wide point of view. This would entail all the data fields
that are required for each table, their data dictionary names and descriptions, their key
fields and the relations between tables. System developers need to know what data is
available in order to design their system, and users need it in order to define their
information requirements. Most of this information is available in the DBMS's data
dictionary.
(S The subschema represents the partial or limited view of the data by an individual user or
application. A student marks processing application (or lecturer) should not be concerned
with a student's personal or financial details, hence the DBMS will only enable access to
the academic record components of the student database.
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Section II 7. Databases
7.5 Database Architectures
Various models or architectures can be used to design an information system. This
architecture is a decision that must be taken up front about the overall functioning of an
information system. It affects the choice of hardware, software and the network configuration.
Although there are many ways to look at database architectures - indeed, the above database
models are also an architectural decision - we will look at the decision which is related to
where most of the data processing should take place
Most business systems have multi-user, networked databases. The user operates a workstation
that requires access to the corporate database. The latter is normally located on a separate,
larger computer. With the evolution in technology, specifically the increasing power of the
user workstations, a decision has to be made about which computer will perform the bulk of
the data processing.
7.5.1 Centralised processing
In a centralised processing environment, the entire processing load is performed by the
central computer, usually a mainframe, to which a number of terminals are connected. This
central and powerful computer is therefore usually referred to as the host computer. The host
controls the data storage and the communication. The application program itself (e.g. a
booking system) also runs on the host computer, which performs the various checks and does
all or most of the data formatting. The terminal itself does almost no data processing, apart
from the most basic screen display formatting instructions.
Although this model was very popular in the early days of mainframe computing, it is now
very much on the wane. It is still found in travel agents (airline booking systems), libraries
and Computicket offices.
7.5.2 Distributed processing
In the distributed computing environment, there is no single host computer that controls all of
the organisation's data. All data resides on individual workstations or, more often, on the file
servers of the LANs of the functional departments or local branches that actually need the
data. These departments' computers are then responsible for all the data processing. This is
the exact opposite of centralised computing. Distributed processing is made possible by the
development of powerful microcomputers with high-capacity hard disks.
In reality, there are two versions of distributed processing. The more common approach is to
divide the entire corporate database in smaller partitions or sections. These partitions are then
distributed on the local network or data servers across the organisations. An alternative
approach is to keep local copies of the entire database on the different local servers. On a
regular basis, usually during the night shift, the servers contact head office and co-ordinate
their changes so that, by the next morning, all distributed databases reflect the changes made
throughout the organisation.
As an example, a national bank could split its customer account database into regional
databases, perhaps one for each province. The transaction details for each account would be
Discovering Information Systems 85
7. Databases Section II
stored in the database of the province where each customer's regular branch is located. Only
when a customer performs a banking transaction at a branch outside her home province,
would there be a need for one regional database to make telecommunications contact with
another.
7.5.3 The client-server model
The client-server model is a compromise between the two extremes of centralised and
distributed forms of processing. Here the processing workload is shared between a central
computer and the local workstation.
Generally, the central computer is responsible for maintaining the database. It runs the
database management system and performs all related functions such as backup, data
integrity, access control and security. This computer issues the required data to the various
workstations that ask for it, and is therefore called the server. The local workstation, the
client, receives the data from the server and is responsible for the presentation of the data. The
term client can also refer to the software that resides on the local workstation i.e. the software
responsible for communicating with the server and formatting the data for on-screen display
and editing.
An ideal example of the client-server model is the World-wide Web on the Internet. Various
web servers around the world hold data available for Internet users to see. Anyone connecting
to the Internet gains access to the web by means of a web browser, which constitutes the
client software. The web browser initiates the contact with the web server, who sends the
requested data (a multimedia document in html format) to the client. The client's web browser
then interprets the various formatting instructions found in the document to present it in the
manner most appropriate for the client computer.
Thin and fat clients
Depending on the amount of processing done by the client, we can distinguish between a thin
and a. fat client. A thin client does little else than the formatting and display of the data; the
real business application software, as well as the data management function, is performed by
the server. This is quite close to the old centralised processing model.
At the opposite end of the scale is the fat client, where the application software resides on the
client computer. All data is processed and checked locally and only the final data records are
transmitted back to the data server. The server runs only the database management system
software; all application software is run on the client.
Two-tier versus three-tier
The client-server model described above is the traditional two-tier (or two-level) model, with
one large server connected to many clients. In a large organisation, it may not be feasible to
split the processing load between the server and the client. What can be done if the database is
very large and needs to be accessed by many users but needs to be kept centralised? If the
organisation's applications are too complex to be delegated to the client, none of the above
models will work. There is too much work for both the server and the client, but the need for
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Section II 7. Databases
one central database precludes the option of distributed processing.
This is where the case for a three-tier client-server model can be made. In the three tier
model, an extra level (or tier) is inserted. At the highest level is the enterprise or central
database server, which runs the data management system to perform all the pure data-related
processing tasks. This server communicates with a number of intermediate, local servers that
run the specific business applications. These servers are usually organised by functional
department or geographic business unit. Finally, the client is responsible for the presentation
and local editing of the data. (In some cases, more than three computers may be involved in
data processing, in which case this is known as an n-tier model.)
A simplistic example is the situation of the inventory database of a large, national
organisation. Because this data is vital to most functional units within the organisation, it
makes sense for the database to reside on one central data server. Each of the applications
which makes use of this database, such as billing, receiving, stock control, etc. could be
located on the various departmental servers located throughout the organisation. One of these
servers might even be a web server that encodes all data in such a way that it can be made
available via the internet to customers who wish to check stock availability. Finally, each user
will interact from his personal computer with the application residing on his departmental
server.
7.6 South African Perspective
The Automated Fingerprint Identification Systems (AFIS) is a mobile system connected to the
police database in Pretoria, that can track down a person's criminal record in a matter of
seconds. The system is being used by police on the East Rand to identify suspected criminals,
as well as to assist in recovering stolen cars. Assistant commissioner Gert de Lange
commented in a newspaper interview that by enabling police to check 100 cars
simultaneously, crime can be targeted with a minimum of inconvenience for motorists.
7. 7 Beyond the Basics
Amazon.com has over 20 million customers and has revolutionized the bookselling business,
becoming a household name almost overnight. Amazon.com succeeded because of the way it
presents information to customers, not just because it was one of the first companies to sell
books via the Web. In fact, it would be difficult to label Amazon.com a bookseller or even a
retailer. It has no brick-and-mortar stores, no warehouses, and little inventory of its own.
What Amazon.com does have is information (lots of it) about customers and what they've
purchased, driven by a foundation of very, very large databases. Amazon.com uses this
information to ensure that customers have a valuable online shopping experience. For
example, Amazon.com proactively recommends books to customers based on previous books
they've purchased, a profile they've filled out, and buying trends among customers who have
similar profiles. The same information capacity is used to support sales of products such as
CDs and clothes.
Amazon.com is an example of a new breed of company whose core business is information
and whose chief competitive advantage is the sophistication of its information systems.
Companies like Amazon.com are dramatically changing the business landscape because they
Discovering Information Systems 87
7. Databases Section II
know how to integrate databases, operational systems, and the Web to cement relationships
with their customers, suppliers, and partners.
7.8 Exercises
7.8.1 Database management system
Pete Anderson owns a small chemist's shop in Wynberg, and recently replaced his cash tills
with a PC-based sales system from Mikrotek Systems that makes use of a product price file,
containing product codes, descriptions and prices, which is updated by his bookkeeper on a
weekly basis.
Pete is so impressed by the accuracy and speed of this system, that he has been looking at
other computer systems that might be suitable for his business. For a reasonable price he can
buy a separate customer accounting system from Aardvark Computing, which will keep track
of his customers' account details and balances, and print monthly statements. As part of the
same deal, Aardvark will also provide him with a stock control system, to be used for
ordering stock and keeping track of what is still available in his storeroom (i.e. has not been
moved into the shop for display or sales).
As he explains it to you, stock orders would be entered on the stock system. When new stock
is received, the quantity available in the store would be increased, and when stock is moved
onto the shop floor, the quantity available in the store would be decreased. Below a certain
stock level, new orders would be automatically generated.
The sales system accumulates totals of sales per day for each product, so that Pete will be
able to identify fast-moving lines and move stock out of the storeroom as needed.
When a sale is made on account, the cashier will simply write the customer's account number
on a copy of the sales docket, which the bookkeeper will then enter into the customer
accounting system the following day.
Pete's son is studying IS, and says that it would be better to install a single integrated database
system which combines all of his business data. Pete is not sure whether his son really knows
what he is talking about, and has asked you to explain why using a database system would be
even more efficient than the solution outlined above, for managing his stock, sales and
accounts.
• Describe three examples of how business activities and record keeping could be
enhanced by the use of an integrated database
• Outline two "queries" or reports that could be useful in managing the business, which
combine data from two or more of the subsystems (stock, sales, customers).
• Design a set of database tables to be used in a new integrated database system that
includes stock, sales and customers. Base your solution on the empty tables provided
below.
Note: Pete needs to keep a record of account holders' names, addresses and telephone
numbers. In addition, account sales to customers must be recorded in the database. Each sale
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Section II
7. Databases
should produce an invoice document which contains an invoice number, date, customer
details, and details of items purchased (item description, quantity sold and value (quantity x
price)). Pete will also keep a record of every product that he stocks (item description,
quantity in stock, price). To assist you in getting started, the optimal solution will consist of 4
tables as labelled below. Complete the exercise by entering all the required fields in the
tables and drawing lines to indicate the links between the tables. You can indicate primary
keys by putting a "P" at one end of the line linking the appropriate fields in the tables.
Customer Table
Stock Table
Invoice Table
Invoice Details Table
Discovering Information Systems
89
Case Study Section II
CASE STUDY: GREENFINGERS GARDEN SERVICES
Refer back to the Greenfingers Garden Services case study that was introduced at the end of
Chapter 3.
(a) Identify the business entities (people, objects or events) about which you would want to
store data. List some of the data fields that would be appropriate for each of these entities,
and their data type (eg text, number, graphic, etc).
(b) It is preferable to capture data as early in an automated business process as possible, since
paper-based recording and later data capture can introduce human error. With this in
mind, who are the people who would be responsible for data capture in a new
computerised information system, and where and when should this data be captured.
(Hint: consider the point at which data is currently first recorded on paper.)
(c) Apart from a standard PC with keyboard and mouse for office use, when would other
devices such as PDAs or cellphones be appropriate, and what sort of interface would they
use?
(d) The classification of applications by function distinguishes general-purpose applications,
business applications, scientific applications and miscellaneous applications. Give
examples of how each of these application types could be used within Greenfingers
Garden Services to support business activities and planning.
(e) Communication of information between work teams, branches, consultants, clients and
central administration is a major problem in the existing manual system. Use a diagram to
show how a combination of data communication methods could support the exchange of
information between them.
(f) Suggest a suitable email address for the business, and list the ways in which email could
be used to enhance business communications.
(g) How would the implementation of a DBMS make Alice Cooper's business administration
easier?
90 Discovering Information Systems
Section III IS Applications
Section III: IS Applications
Although computer-based information systems are a relatively recent phenomenon, having
been around less than half a century, we can already distinguish a number of stages through
which they have progressed.
• During the nineteen fifties and sixties, the main focus of the systems was the automation of
operational data flows: the era of electronic data processing. (EDP) These systems
assisted operational (white collar) staff with their information work.
• In the seventies and early eighties, the extraction of the data for managerial decision
making became much more pronounced and this introduced the need for management
information systems and decision support systems. This was made easier by the maturing
of the technology, in particular the existence of more powerful mainframe computers with
plenty of disk storage that could support a database approach to applications. Information
systems started to assist and improve the quality of managerial decision making.
• The late eighties and nineties saw the rise of end user computing which necessitated
distributed access to data. This is also the period where the limitations of functionally
oriented applications were being felt due to the increasing competitiveness in the markets,
and to the associated rapid increase in required response time. Major redesigns resulted in
the advent of more integrated, process-oriented enterprise systems. During this period,
more and more organisations used the capabilities of systems based on innovative
technologies to develop new products or services, or dramatically alter the way in which
these were being delivered to the customer. This is the birth of strategic information
systems: systems that are deployed to gain a competitive edge in the market.
• Increasing globalisation, coupled with the sustained increase in the capabilities of the
computer and communications technologies, has led to more pronounced emphasis on the
integration of information systems within (intra-) and between (inter-) organisations.
There is much greater convergence between communications, computer and media
technologies whereby a number of information processing technologies are linked
internally and externally. The continued miniaturisation and networking is likely to make
information systems much more mobile, embedded and pervasive in the work and home
environment. The use of international standards and maturing of underlying technologies
will shift the emphasis even further from the technology (the how) towards the
management, human and deployment issues (the what and where).
With the growth of the internet, electronic commerce is playing an increasingly important role
in linking organisations with their customers and their business partners, and is becoming an
essential component of the IT strategy of modern businesses. E-commerce enables market
expansion with minimal capital outlay, improves procurement and marketing and increases
consumer choice; but there is still a need for universally accepted standards for information
quality and security, and the provision of sufficient telecommunications bandwidth.
This section of the textbook will examine different types of IS applications in more detail,
focusing on how they are used within and beyond organisational boundaries, as well as the
Discovering Information Systems 91
IS Applications Section III
growing business importance of electronic commerce. Since these applications are used by
human beings, and so are vulnerable to deliberate abuse or accidental misuse, we will also
address a number of security related issues.
92 Discovering Information Systems
Section III
8. Business Support Systems
8. Business Support Systems
As discussed in Chapter 1, different types of information systems are used by the various
management levels of an organisation. They support the objectives of the business by
increasing the efficiency of business processes, cutting supply costs, improving levels of
customer service and improving managerial decision-making.
• Transaction Processing Systems record routine transactions within the different
departments of an organisation;
• Management Information Systems draw from the TPS to monitor and control business
performance;
• Decision Support Systems and Executive Information Systems assist managers with
complex decision- making tasks;
• Strategic Information Systems make use of information technology to gain
competitive advantage;
• an increasing number of Intelligent Systems are being incorporated within business
processes to extend IS capabilities;
• Data Mining and On-Line Analytical Processing can be used to search through
organisational data to uncover previously unknown patterns and trends.
8. 1 The Decision-Making Process
Across all levels of the organisation, information is used as the basis for decision-making by
operational and management staff. Figure 8-1 illustrates the various steps of the typical
decision making process.
Collect data about the
decision or problem
A
Feedback: can
the decision be
improved?
Implement the most
desirable option
If no aci
Generate a number
of alternatives
stable alternative
^bund, collect
itional data
Evaluate each of
the alternatives
Figure 8-1: Steps in the decision-making process
The type of decision to be made generally depends on the level within the organisation.
Clerks typically make routine decisions based on clear guidelines. Top-level managers are
faced with more uncertainty and the decision process is correspondingly much more
unstructured.
This dichotomy of information work is reflected in Figure 8-2, which contrasts the two
extreme types of decision, sometimes referred to as Type I and Type II decisions. In practice,
most decisions fall somewhere between these two extremes and share some characteristics of
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both Types I and II, although decisions made by clerical staff are likely to be closer to Type I,
and decisions made by senior management will incorporate more Type II characteristics.
Because of this, the information systems used at higher levels of the organisation tend to be
more complex: it is far simpler to automate the decision as to when paper for the photocopier
should be re-ordered, than to decide whether to introduce a completely new product.
Although the different types of information systems may be described under separate
headings, integration between them is vital if the information flows within the organisation
are going to successfully meet the needs of a wide range of users, who may be making
decisions affecting more than one functional area of the business, based on data from a variety
of different sources.
Type I Type II
Many transactions/decisions
Relatively few transactions/decisions
Low value or cost per transaction
High value or cost per transaction
Well-structured and detailed procedures
and guidelines
Ill-structured and vague procedures and
guidelines
Output, objectives and evaluation
measures well defined or specified
Output, objectives and evaluation measures
less defined
Process-oriented
Problem or goal oriented
Emphasis on efficiency: "do the thing
right"
Emphasis on effectiveness: "do the right
thing "
Processing of mainly structured data
Handling of concepts, information
Predominantly clerical workers
Managers and professionals
Examples: processing of orders,
payments, first-line customer queries
Examples: planning, crisis management,
design
Figure 8-2: The dichotomy of information work: two decision extremes
8.2 Batch vs Online Processing
In early commercial systems, data was usually entered into an organisational information
system in batch mode, mainly because computer technology had not yet been developed to
support more advanced systems. Here the practice was to manually record each business
transaction, and then later enter the corresponding data into the computer. At regular intervals
(e.g. at the end of each day) the master files would be updated to show the new balances, and
related customer documents such as invoices would be generated. Management requests for
information about the state of the business would be based on the most recently updated files.
This approach gave rise to a number of problems: poor authorisation checks; incorrect data
94
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recorded on the original invoice would only be picked up much later; new errors could be
introduced at the data capture stage; documents could go missing before they were captured;
and management information was usually out-of-date.
On-line entry systems overcame some of these problems. By capturing data electronically at
the time that a transaction occurs, authorisation and data correctness can be automatically
verified, and the opportunity for human errors to be introduced at a later stage is removed.
However, updating of master files still takes place at predetermined intervals, and not at the
time of each transaction, so management reporting remains unreliable. Nevertheless, this type
of system remains popular for applications such as payroll, where information only needs to
be produced periodically.
With decreasing computing costs and the need to remain competitive, on-line update (or
realtime) systems have now become the norm. Each transaction is recorded directly on to the
computer (often by means of a bar code scanner); the data is immediately validated and the
relevant master files are updated. To achieve this, each point-of-sale (POS) terminal must be
connected via a network to the central database containing customer records, stock records,
and other sales-related data. As soon as the transaction has been completed, invoices and
other documentation are produced. Opportunities for fraud are limited, since data is validated
at the time of entry and source documents cannot disappear before their details are captured.
Although some reports such as customer statements may only be needed periodically, the data
in the database is always up to date and is available to managers at any time.
Recording
of Source
Customer
Documents
Transaction
1
f \
D
A
T
^
Input Validation
and Update
A
B
■
r
Customer Documents
A
s
^
End of Cycle
E
Repo
rting
Reports
Figure 8-3: On-line transaction flow
In recent years, online transaction processing has broadened to include transactions entered
via the Internet.
8.3 Applications at Different Management Levels
8.3.1 Transaction Processing Systems
Transaction Processing Systems support simple processing of large amounts of structured
data. This data is mainly of internal origin, resulting from numerous routine transactions that
occur in many different business areas. Common modules of a TPS include:
• Order processing: orders for goods or services can enter the system from customers,
salespeople, or other internal departments.
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• General ledger: details of all transactions affecting the accounts of the company are
recorded to simplify bookkeeping and reporting.
• Accounts payable and receivable: data generated from sales journals or purchase
orders can be used to improve debt collection and cash flow.
• Inventory management: along with updating of stock levels, IS is commonly used for
tracking of materials and for linking the organisation to suppliers and purchasers.
• Payroll: employee details, earnings, deductions, leave accrual etc.
8.3.2 Management Information Systems
Management Information Systems (MIS) are systems that use the data generated by the TPS
to help lower and middle management in their decision making. MIS use a variety of
techniques to process, summarise and present the information in the form of useful reports:
tables, statistics, graphics, etc. Many MIS can easily be customised and new reports are
readily created on demand. Because many businesses are still organised on a functional basis,
many MIS tend to focus on specific functional areas e.g. a marketing MIS, a human resources
MIS etc. The decisions taken by middle management are more complex than pure operational
decisions. They involve a longer, medium-term time span (typically looking several months
ahead), influence a large number of individual operational decisions (e.g. price setting,
carrying or dropping new stock items, changing procedures etc.) and are less structured than
operational decisions, though they do tend to follow certain patterns and be of a recurrent
nature. These decisions are called tactical management decisions. They typically affect the
whole or a major part of a functional department (e.g. the entire marketing department) and
involve more significant resources than operational decisions.
A particularly useful feature of MIS are the so-called "exception reports" which list only
unusual or abnormal transactions, namely those that fall outside the normal pattern; instead of
many, many pages of detailed data, the manager sees only those items which may require
special attention or corrective action. An exception report for a bank manager might list all
transactions exceeding one million rand; or those bank departments who have exceeded their
budget by more than 10%.
Organisational support provided to business managers by the MIS commonly includes
financial planning and budgeting, investment management, financial controls, marketing
management and the provision of customer service.
8.3.3 Decision Support Systems
Decision Support Systems (DSS) are systems that assist managers with very specific types of
decision-making situations. Though they are often used by the same managers who also rely
on MIS, a distinguishing feature is their modelling capability. DSS use various mathematical
and statistical models to help the manager generate alternative decision options and evaluate
their outcomes. Another difference between DSS and MIS is their time perspective: an MIS
typically produces reports based on historical information where a DSS allows the manager to
see the future impact of his decision. Table 8-4 lists some more differences between MIS and
DSS.
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MIS DSS
Problem type
Mainly for more structured
problems or programmed
decision-making.
Good at handling unstructured
problems.
Support
Provides only the information
necessary to make a decision.
Supports all stages in the decision
making process, including the
modelling and evaluation of various
decision alternatives.
Approach
Typically based on regular,
structured reports.
Excels at interactive and ad-hoc
queries.
System
Often based on printed reports,
via batch mode, delivered to
managers on a regular basis.
On-line and real-time interaction,
mainly screen oriented.
Speed
Requires a greater turn-around
time and is less flexible in
terms of report format
changes.
Quick
Development
By IS staff.
Often by end users.
Table 8-4: Some differences between MIS and DSS
When information is required to support management decision making, the user of the DSS is
able to interact directly with the computer via a graphical user interface or control language to
request the relevant data, select and operate the appropriate decision model and generate the
output report in the format required. The following diagram of a DSS shows the three main
components; the database, model base and user interface.
Model Base
User
Interface
User
^ w
DSS
Database
Figure 8-5: Components of a Decision Support System
DSS Database. This database contains current and historical data from all the relevant
business applications. However there are a number of good reasons why organisations do not
allow the DSS to access the operational database used by the transaction processing systems,
but rather construct another database for this purpose. One key reason for limiting access to
the operational database is that DSS requests often require many passes of the database to
select the required data. This activity will impact on the service the DBMS can provide to on-
line applications in areas where response times are critical. In addition, while DSS systems
normally download a copy of data for analysis and seldom update the database, management
is always concerned about the security and integrity of the operational database and prefers to
limit access to a minimum. Finally it makes good sense to maintain a database specifically for
DSS queries. In the DSS database, some data need be held only in summary form while
certain historical records must be retained for a five year period to allow for trend analysis. In
some cases the data may come from different databases, sometimes held on different
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hardware and software platforms, and the transfer (and potential reformatting) of data to a
common DSS database enables queries to be generated combining data from these varied
sources. With the demand for end-user access to current and historical information, many
organisations are building data warehouses, which store large quantities of data obtained
from different functional areas of the organisation.
Model base. This is a library of analytical tools that can be used to evaluate and represent
data. Typical examples are the standard business functions (for example to calculate
discounted cash flows and depreciation), statistical functions (means, standard deviation and
variance), data retrieval tools to select, sort and summarise, and the ability to test possible
scenarios through sensitivity analysis and goal seeking.
User Interface. In the past managers communicated their report requirements to
programmers who coded the request and delivered the required output. The nature of
management decision making is such that response time is often critical. In addition the
solution to problems of this nature is iterative, as one report may trigger the need for alternate
investigations into other areas of the business. Often senior managers use a 'chauffeur', an
analyst or skilled end user to assist them in developing the required DSS output. Obviously
the most suitable DSS environment is to have the decision maker interface directly with the
DSS. Graphic user interfaces and the increased level of computer literacy within the
management hierarchy, have made this possible.
When a user requires a report or enquiry to be performed by the DSS, he or she will enter the
request in a high level, user friendly business language. For example, by clicking the mouse
on options and items in list boxes, the user can pick fields, choose selection criteria, detail
sequence and request the level of detail for a particular report. The user interface software will
then translate this request into the code required to perform the process using the required
data and business rules. These user interfaces also offer sophisticated output formatting with,
for example, the results being presented in text format or as business charts.
8.3.4 Executive Information Systems
Decisions made by top-level executives are often too unstructured to be adequately supported
by a DSS. For this reason, Executive Information Systems (EIS) have been developed, which
provide rapid access to both internal and external information, often presented in graphical
format, but with the ability to present more detailed underlying data if it is required.
An EIS will continuously monitor selected key performance indicators that have been
identified as critical to the success of the organisation. The user will be alerted to any
significant changes that occur, and "drill-down" capabilities will then provide further levels of
detail underlying this information. Trend analysis can be done using forecasting models,
usually through the integration of the EIS with a DSS system.
8.4 Strategic Systems
An important special type of organisational information system is used to secure or sustain
competitive advantage in the market place: strategic information systems. Although these
systems generally form part of a more generic business marketing strategy, the information
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Section III 8. Business Support Systems
technology is actually a critical enabler or support element to achieving success in the market.
The following three possible strategies are typically distinguished.
•
Low-cost strategy: use of the information systems to produce significant cost-savings and
thus offer services/products at a lower price than competitors (or increase profit margins).
One typical example is the use of alternative marketing or distribution channels such as
using the Internet for receiving orders and eliminating middlemen such as wholesalers and
retailers. Another example is having more integrated or even completely redesigned
logistics processes such as having a fully automated on-demand production line where
parts and components are supplied on a just-in-time (JIT) basis by the suppliers, often
using an Electronic Data Interchange (EDI) system.
• A differentiation strategy: use of information systems to provide a distinctive quality or
otherwise add value to your products or services. Technology can enhance quality through
better manufacturing processes (e.g. a quality control system or automated manufacturing)
or add value by increasing the information content or information intensity of the
service/product. Other possibilities are the use of computer and communication
technologies to enhance after-sales support e.g. automated (self-)diagnostics, remote
diagnostics, direct internet support and help-line.
• A niche marketing strategy: using information systems technology to service very small,
isolated or exclusive markets that have specific demands. A good example is the
publishing industry: the ability of the internet to reach individuals with extremely specific
interests for whom there would otherwise be no cost-effective marketing or distribution
channel allows the marketing of extremely specialised books. Another example in the
publishing technology is the production of small print runs of "customised textbooks on
demand" whereby course lecturers can compile individually customised textbooks made
up of different modules tailored to their specific curriculum requirements.
8.5 Intelligent Systems
The traditional approach to solving problems using a computer is to provide instructions to
the machine (in the form of a program) detailing exactly how the task is to be performed.
However, some tasks are seen as too unstructured (ill-defined) to be programmable. For
example imagine writing a program to control a robot housekeeper. The number of possible
situations the robot needs to identify and respond to are so great that conventional
programming techniques are totally inadequate. Add to these problems the concept of
approximate or fuzzy logic. Pure propositional logic (things are either true or false) is too
exact for real world problems where humans are required to make guesstimates based on
probabilities.
The ability of computers to work intelligently (and not just follow a set of standard
instructions) has fascinated scientists, researchers and sci-fi writers since the early 1950s, and
artificial intelligence (AI) is the branch of computer science concerned with understanding
the nature of human intelligence with the goal of simulating aspects of it with a computer.
While we still know very little about how the brain functions, there are four areas of AI
research that have made some progress towards the goal of an intelligent machine:
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• Natural languages: the ability for computers to understand the spoken word
• Robotics: where machines perform co-ordinated physical tasks
• Visual perception: the ability of machines to recognise visually shapes and objects
• Expert Systems: systems developed to simulate the decision-making behaviour of
humans in a narrow area of expertise.
8.5.1 Expert Systems
Expert systems (often termed knowledge-based systems) are the category of AI which has
been used most successfully in building commercial applications. As discussed earlier,
attempting to provide computers with the intelligence to handle complex real world
environments is beyond our current capabilities. However expert systems are knowledge
intensive programs that capture the expertise of a human within a narrow problem domain.
In order to address a particular problem area (for example to diagnose a disease in a sick
patient) the expert system must have a knowledge base (a database of facts, intuition and rules
about the knowledge domain) and an inference engine (software capable of manipulating
knowledge contained in the knowledge base). Since knowledge takes many forms and shapes
(facts, rules, relationships between facts and rules, probabilities, defaults and exceptions,
models, contradictory statements and many other non-structured items), standard database
models such as the relational model are not always suitable. Several different knowledge-
based databases have been developed for use in expert systems, although despite attempts at
standardisation, most of them use their own proprietary ways of representing and dealing with
the data.
There are already many commercial examples of expert systems being used across a range of
applications such as the diagnosis and treatment of medical conditions, the evaluation of loan
applications, and the identification of mineral deposits.
8.6 Data Mining and OLAP
8.6.1 Data warehouses
Business managers have only recently started to realise how much valuable information is
hidden inside the many different databases underlying their information systems. Data
warehouses can be used to correlate and analyse the information contained in different
databases within the same organisation. Usually, a copy of the continuously changing
transaction data within the various operational databases is made periodically into one single,
huge database: the data warehouse. This data warehouse then contains detailed historical data
for all or most of the organisation's operations. Powerful statistical and charting tools assist
managers in comparing and analysing the data.
Effective construction of a data warehouse must provide facilities to integrate data from
different functional areas of the business, which may be represented using different formats.
Software programs will extract data from its original source, convert it into a uniform format
and then store it in the warehouse.
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Sometimes it is technically not feasible or it is too expensive to merge the data from many
databases. In those cases, some benefit can already be had from focussing on the
organisation's most important databases, usually the ones relating to customers and sales.
Such a mini data warehouse focussed on one particular functional area is called a data mart.
8.6.2 On-line analytical processing
Imagine a marketing manager trying to analyse this quarter's sales to discern trends and
pinpoint problem areas. How can the data be analysed? There are many possible views.
According to different product groups.
Using the time dimension, comparing the different months.
Looking at the cost components and contribution to income.
Comparing sales budgets, projections, actual sales and variances.
Analysing sales according to geographic region.
Evaluating the various marketing channels: wholesales, sales force, brokers and the
corporate market.
On-line analytical processing (OLAP) is concerned with the real-time analysis of large
corporate databases to find trends and inter-relationship by managers and decision-makers.
The user formulates complex queries and searches by means of sophisticated, interactive
front-end applications such as statistical packages, spreadsheets or decision support systems.
Because traditional database models are not very good at handling and displaying many
different dimensions of business data for simultaneous analysis, multidimensional analysis
technologies are used to filter and aggregate subsets of the data. Advanced statistical analysis
tools and graphical interfaces are incorporated to facilitate data visualisation, often using
hypercubes to display multidimensional information.
MODEL
REGION
YEAR
Figure 8-6. Example of a hypercube (www.ssa-lawtech.com/ wpZwp2-3.htm)
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The raw data is often derived from traditional application databases, but because of the huge
amounts of data processing involved, a separate server may be used to store and process the
data subsets being used for analysis. This approach gives rise to a three-tier model, which
includes the server or mainframe which hosts the organisational database, the workstation on
the manager's desk through which queries are submitted, plus a dedicated OLAP server
holding relevant subsets of data in multidimensional databases. Unlike an executive
information system, this does not usually provide the ability to "drill down" to the level of the
original transactions underlying a query result.
8.6.3 Data mining
The huge amount of information and the many possible different perspectives often make it
very difficult for humans to discern meaningful trends within the masses of data in the data
warehouse. Statisticians have developed a number of methods that automate the discovery of
non-random trends and significant inter-relations. Data mining is the use of these statistical
methods, packaged in a single computer package and let loose on their own, without human
intervention, to discover deep or hidden data interrelationships.
8.7 South African Perspective
An example of a locally developed system that supports business transactions, management
control and decision-making is Digitot, a computerised beverage-dispensing system.
Traditionally, the hospitality industry loses between 10% and 25% of revenue on alcoholic
drinks, due to spillage, pilferage and "freebies", and frequent manual stocktakes are
necessary. The Digitot system, which is integrated with a point-of-sale system, uses electronic
tot measures to digitally dispense and count each tot and automatically update stock levels.
Flexible reporting over selected periods can analyse this data to determine when stock has
gone missing and who was responsible for the loss. Data analysis can also reveal patterns in
customer preferences and identify products that offer value for money, which can be used as
the basis for promotional marketing.
8.8 Beyond the Basics
Neural networks are proving increasingly valuable in complex decision-making, where a large
number of factors must be simultaneously considered and human inconsistency or prejudice
could affect the decision outcome. Furthermore, they are able to adapt to changes in the
business environment over time. The neural network consists of many cooperative processing
elements, that are "trained" using a large number of historical transactions (the data that was
evaluated and the outcome that was reached) in order to establish criteria that can be applied
to future decisions. The weighting of these criteria will subsequently change over time, since
each new application of the neural network may affect the previous relationship between
elements.
Neural networks are particularly useful when processing complex data for which no
established decision rule is known, or when there are too many variables to consider. In this
case, it is easier to let the network learn from examples.
Neural networks are being used:
102 Discovering Information Systems
Section III 8. Business Support Systems
• in investment analysis: to attempt to predict the movement of stocks currencies etc.,
from previous data. There, they are replacing earlier simpler linear models.
• in monitoring: neural networks have been used to monitor the state of aircraft engines.
By monitoring vibration levels and sound, early warning of engine problems can be
given.
• in marketing: neural networks have been used to improve marketing mailshots. One
technique is to run a test mailshot, and look at the pattern of returns from this. The
idea is to find a predictive mapping from the data known about the clients to how they
have responded. This mapping is then used to direct further mailshots.
8.9 Exercises
8.9.1 Processing methods
Compare a batch processing system (such as might be found in a hardware store) with a
realtime processing system (e.g. in a bank), in terms of the authorisation methods used to
check the identity of the customer, how the initial transaction details are captured, the
completeness of transaction data, opportunities for human error to enter the process,
availability of data for managerial decision-making.
8.9.2 Organisational information flows
Construct a diagram to show how data and information flow between the different types of
organisational information systems (TPS, MIS, DSS, EIS), and their users, data stores and
environment.
8.9.3 Fuzzy logic
Fuzzy logic refers to a type of expert system which caters for non-binary decision-making (i.e.
not simply a yes/no answer). For example, when you buy a car, you might be satisfied (in
varying degrees) with petrol consumption falling within a range, rather than arbitrarily
selecting a cutoff point below which it is okay and above which it is unacceptable. Search on
the Internet or in an IS textbook to find a simple explanation of the concept of fuzzy logic,
and an example of how it has been implemented in commercial devices.
Discovering Information Systems 103
9. E-Commerce Section III
9. E-Commerce
Business was quick to grasp the marketing and business potential offered by the Internet.
Initially, businesses used the Internet to facilitate communication by means of e-mail. This
was quickly followed by tapping the web's potential for the dissemination of product and
other marketing information. The provision of advertising space {banners) on frequently
visited web sites is the main source of income for search engines (sites allowing you to search
the Internet for information) and web portals (web sites that provide additional value-added
personal services such as news, financial information, weather forecasts, items of interest etc.)
A number of specialised companies have realised that the Internet can be a direct and
extremely cost-effective channel of distribution. Some companies already have a physical
infrastructure and use the web to enhance their distribution channel e.g. you can now order
your pizza, bank statements or movie tickets via the web. Other, virtual companies have
almost no physical infrastructure and are mere "conductors" for the flow of products of
services.
Important categories of e-commerce include:
• Business-to-consumer (B2C) in which organisations provide information online to
customers, who can in turn place orders and make payments via the internet
• Business-to-business (B2B) in which business partners collaborate electronically
•
Consumer-to-consumer (C2C) in which individuals sell products or services directly
to other individuals.
The technologies that are needed to support electronic commerce include the network
infrastructure (Internet, intranets, extranets), software tools for web site development and
maintenance, secure ordering and payment methods, and resources for information sharing,
communication and collaboration. When e-commerce is done in a wireless environment, such
as through the use of cellphones, this is referred to as mobile commerce (m-commerce).
9. 1 B2C e-Commerce
Electronic retailing is similar in principle to home shopping from catalogues, but offers a
wider variety of products and services, often at lower prices. Search engines make it easy to
locate and compare competitor's products from one convenient location and without being
restricted to usual shopping hours. Electronic malls provide access to a number of individual
shops from one website. On-line auctions have also proved a popular way of disposing of
items that need a quick sale.
Business-to-consumer commerce allows customers to make enquiries about products, place
orders, pay accounts, and obtain service support via the Internet. Since customers can enter
transactions at any time of the day or night, and from any geographical location, this can be a
powerful tool for expanding the customer base of a business. However, the existence of a
website does not guarantee that customers will use it, or that they will return to it after a first
visit. Firms investing in electronic commerce need to consider a number of factors in
developing and maintaining their e-commerce sites.
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Section III 9. E-Commerce
A successful web site should be attractive to look at and easy to use. In addition, it should
offer its customers good performance, efficient service, personalisation, incentives to
purchase and security. Inadequate server power and communications capacity may cause
customers to become frustrated when browsing or selecting products.
Many sites record details of their customers' interests, so that they can be guided to the
appropriate parts of the site. Customer loyalty can also be developed by offering discussion
forums and links to related sites, and by providing incentives such as discounts and special
offers for regular customers. And if you expect customers to purchase goods, and not just
browse, then it is vital that customers should have complete confidence in the security of their
personal information, and in the ability of the web store to deliver the goods as requested.
Much of the business value of the Internet lies in the ability to provide increased value to
customers, with the focus on quality of service rather than simply price. By opening
additional channels of communication between the business and its customers, businesses can
find out the preferences of their customers, and tailor products to their needs. Customers can
use the Internet to ask questions, air complaints, or request product support, which increase
customer involvement in business functions such as product development and service.
However, although businesses may increase their markets while gaining from reduced
advertising and administration costs, problems that have emerged include alienation of regular
distributors, difficulty in shipping small orders over large distances, fierce competition and
inadequate profit margins. Because of the delivery problem for physical products, many
successful e-commerce firms have focused on the delivery of services, such as banking,
securities trading, employment agencies and travel bureaus. Of course, every problem can be
regarded as an opportunity - a local software developer has created and marketed a route
scheduling application which provides optimised route sheets, with maps for individual routes
and step-by-step driving instructions for effective and timeous order management, based on
powerful geographical information systems to provide a user-friendly interface.
B2C e-commerce has also made it easier for firms to conduct market research, not only by
collecting shopping statistics, but also by using questionnaires to find out what specific
groups of customers want. This in turn has enabled the personalisation of products to meet
customer preferences.
9.2 B2B e-Commerce
Business-to-business e-commerce comprises the majority of electronic transactions, involving
the supply chain between organisations and their distributors, resellers, suppliers and other
partners. Efficient management of the supply chain can cut costs, increase profits, improve
relationships with customers and suppliers, and gain competitive advantage. To achieve this,
firms need to
• Get the right product to the right place at the least cost;
• Keep inventory as low as possible while meeting customer requirements;
• Reduce cycle times by speeding up the acquisition and processing of raw materials.
Discovering Information Systems 105
9. E-Commerce Section III
Information technologies used to support business-to-business e-commerce include email,
EDI and EFT, product catalogues, and order processing systems. These functions may be
linked to traditional accounting and business information systems, to ensure that inventory
and other databases are automatically updated via web transactions. Intranets provide a
facility for members of an organisation to chat, hold meetings and exchange information,
while at the same time sensitive information is protected from unauthorised access by means
of a firewall. An extranet provides a means of access to the intranet for authorised users such
as business consultants.
Electronic data interchange (EDI) involves the electronic exchange of business transaction
documents over computer networks, between organisations and their customers or suppliers.
Value-added networks provided by third parties are frequently used for this purpose.
Documents such as purchase orders, invoices and requests for quotations are electronically
interchanged using standard message formats, which are specified by international protocols.
EDI eliminates printing, postage and manual handling of documents, reducing time delays
and errors, and thus increasing productivity. It also provides support for implementing a Just-
in-Time approach, which reduces lead time, lowers inventory levels, and frees capital for the
business.
Marketing to other businesses is done by means of electronic catalogues and auction sites,
which can increase sales while reducing advertising and administrative costs. From the
buyer's perspective, reverse auctions can be used to advertise requests for quotation in a
bidding marketplace in order to attract potential suppliers. Third party vendors can make use
of group purchasing to aggregate a number of separate small orders in order to increase
negotiating power.
Collaborative commerce involves long-term relationships between organisations in areas such
as demand forecasting, inventory management, and product design and manufacture.
However, this presents a number of business challenges such as software integration,
compatibility of technologies, and building of trust between firms.
9.3 C2C e-Commerce
Auctions are the most popular method of conducting business between individuals over the
Internet. (Unfortunately, auction fraud was also the most common type of crime reported to
the Internet Fraud Complaint Centre in 2002.) Other C2C activities include classified
advertising, selling of personal services such as astrology and medical advice, and the
exchange of files especially music and computer games.
9.4 Electronic funds transfer
Electronic payment systems can be used to transfer funds between the bank accounts of a
business and its suppliers, or from a customer to the business. In retail stores, wide area
networks may connect POS terminals in retail stores to bank EFT systems. In most cases, an
intermediary organisation acts as an automated clearinghouse, which debits and credits the
relevant accounts.
The most popular payment method used by individual consumers is the credit card, which
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9. E-Commerce
requires the merchant to pay a commission to the bank on each transaction. For transactions
involving small amounts that do not justify the payment of commission, merchants may
accept electronic money in the form of digital cash In this case, the customer "buys" money
from the bank in the form of a unique cash number, which is transmitted to the merchant at
the time of purchase and "deposited" in an account at a participating bank. In South Africa
several banks have developed their own forms of digital cash, such as e-bucks from First
National Bank.
Figure 9-1. Stages in an e-commerce transaction (www.artboomer.com/images/commerce.asp)
An important issue in electronic commerce is the security of Internet transactions. Data is
commonly encrypted to reduce the vulnerability of credit card transactions. Secure Sockets
Layer (SSL) and Secure Electronics Transaction (SET) are two of the standards used to secure
electronic payments on the Internet. Secure sites usually have URLs that begin with https
instead of the usual http.
9.5 Current issues in e-commerce
For e-commerce to succeed, companies need to make large investments in hardware and
telecommunications infrastructures that will be up and running 100% of the time, and
software that is easy to use and reliable. A number of early participants in the e-commerce
market suffered financial losses because their technology was not able to handle the huge
numbers of transactions to be processed. Internet customers are often impatient, and will
move to a competing site if the response is too slow.
Gaining the trust of customers can be difficult - the seller is often reluctant to despatch goods
before payment, and the buyer may be reluctant to pay before receiving the goods. In South
Africa, the speed of electronic ordering is often negated by delays in physical delivery.
Societal problems have also emerged, with children, gamblers and shopping addicts enjoying
unrestricted access to electronic commerce sites. A German cannibal posted a web
advertisement seeking a victim who was willing to be killed, sliced and eaten - and
apparently found one! (reported in www.iol.co.za, 18 December 2002). The laws governing
electronic commerce are still in their infancy, and international standards need to be
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developed in areas such as information privacy and taxation.
Since e-commerce supports global business transactions, it presents the challenge of
customising web sites to appeal to people of different nationalities and cultures (and even
different languages). South Africa's leading role in e-commerce in Africa can probably be
attributed to the fact that it has a relatively advanced telecommunication infrastructure and a
large number of English-speaking users.
9.6 South African Perspective
Because a website can easily be developed as a front for a fraudulent company, businesses
need a way to guarantee their authenticity to potential customers. Thawte Consulting, the
company established by Mark Shuttleworth after graduating from UCT and later sold to
market leader Verisign, provided (among other products) digital certificates which serve two
purposes: to ensure that no sensitive information can be viewed by unauthorised users, and to
provide users with assurance regarding the ownership of the site. By providing certificates at
a lower cost than its competitors, but with similar technological and security standards,
Thawte rapidly established itself as the second largest provider of digital certificates.
These non-forgeable Secure Sockets Layer (SSL) certificates are issued and digitally signed
by a company such as Thawte, which has verified that the website really is owned by the
organisation requesting the certificate. Once the digital certificate has been installed on the
site, the SSL uses complex encryption techniques to scramble confidential information.
9. 7 Beyond the Basics
Encryption is the process of converting readable data into unreadable characters to prevent
unauthorised access. Encrypted data can be safely transmitted or stored, but must be
decrypted before it can be read, by using an encryption key, which is sometimes the same
formula that was used to scramble it in the first place. Simple encryption methods include:
• Transposition: in which the order of characters is switched, for example each pair of
adjacent characters is swapped.
• Substitution: in which each character is replaced by some other predetermined
character.
• Expansion: additional letters are inserted after each of the characters in the original
text.
• Compaction: characters are removed from specific positions and then stored or
transmitted separately.
Most encryption programs use a combination of all four methods.
Private key encryption relies on both sender and recipient having access to the same
encryption key. Public key encryption makes use of two keys: a message encrypted with your
public key can only be decrypted using your private key. This means that you can safely
communicate your public key to business contacts, who are then able to send you confidential
data that can only be read using your private key. Security agencies in the United States have
108 Discovering Information Systems
Section III 9. E-Commerce
lobbied for some time for private keys to be independently stored, so that encrypted
communications could be monitored when national security is considered to be at risk.
9.8 Exercises
9.8.1 B2C e-commerce
What advantages does the customer stand to gain from B2C e-commerce, compared with
traditional business models?
Can you think of any potential disadvantages?
9.8.2 C2C e-commerce
Give reasons why internet auctions are a common source of fraud, and suggest control
structures that could be put in place to reduce this problem.
9.8.3 B2B e-commerce
Explain how B2B ecommerce could contribute to each of the alternative strategies for
competitive advantage (low-cost, differentiation, niche marketing) that were described in the
previous chapter.
Discovering Information Systems 109
10. Security and Social Issues Section III
10. Security and Social Issues
We all know why computers are taking over from human processors. They are much cheaper
in terms of their cost/performance, can handle large volumes of transactions at great speed, do
not make mistakes, are not members of workers' unions and do not take holidays or sick
leave. In the early 1980's the computer was still an object of some mystery, hidden in large
buildings and operated by specialist personnel. Today the computer is everywhere: in every
office and many homes; and individuals with limited or no computer expertise are becoming a
minority.
However, computers also offer new opportunities for fraudulent and illegal activities. Well
publicised computer crimes of the last decade have included:
• The Equity Funding Disaster. The top management of Equity Funding created billions of
dollars of bogus insurance policies and sold them on to re-insurers. The motivation was to
survive a serious cash flow problem and the intention was to buy back the policies and
hide the fraud when the business began making money again. Unfortunately the problem
persisted and the fraud grew to such proportions that the company actuary calculated that
soon they would have insured more phony people than the entire population of the United
States.
• Mamalodi Sundowns vs Standard Bank. The owner of a South African football team
required funds to purchase players and support an extravagant life style. His girl friend
was working in the head office of a large bank and was responsible for allocating inter-
branch transfers of funds from one account to another. Over a three year period she
transferred over RIO million into accounts controlled by her friend and covered the fraud
by moving new funds into the accounts previously stripped. Like most frauds of this type,
they can remain undetected for many years until the staff member is not available to
continue the manipulation. The individual went on holiday for a week and her replacement
noted some irregularities and called in the auditors to investigate.
• The Rifkin Caper. A computer contractor to a Californian bank used his inside
knowledge to find the necessary passwords to authorise electronic transfers of money, and
made a $12 million transfer from a client's account to a Swiss bank account under his
control. He then travelled to Switzerland and purchased diamonds with the funds. Back in
the USA he was apprehended in a police trap while trying to sell the diamonds. Of interest
is the fact that the client only discovered the loss of the original funds when police
enquiries concerning the diamonds began. The contractor's name was Rifkin and he
almost escaped going to prison because of technical irregularities in police arresting
procedures. He has since served his time in jail and is now a computer security consultant.
Because much of the data processing that takes place in an information system is not visible
to the naked eye, controls must be built in to ensure that business transactions are correctly
recorded and processed. This chapter also looks at some of the threats faced by computer
systems, and discusses how the computer has changed our daily lives, both at work and in the
home.
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Section III 10. Security and Social Issues
Some of the issues that are addressed in this chapter include
• security within the organisation: fraud and access control
• security beyond the organisation: hackers and viruses
• computers and unemployment
• operational problems and errors
• computer monitoring and invasion of privacy
10. 1 Security Within the Organisation
Security risks within an organisation include the processing of fraudulent transactions,
unauthorised access to data and program files, and the physical theft or damage of equipment.
10.1.1 Fraud
Computer fraud is increasing at an alarming rate. Fraud can be defined as the manipulation of
the records of an organisation to conceal an illegal act (normally the theft of funds or other
assets). Computers can make it easy for employees in particular to defraud the organisation, in
particular when the level of security and internal control is lax. In manual systems, a common
control to limit fraud is to involve two or more people in a process, each one effectively
controlling the activities of the others. We call this control process separation of duties. For
example in a payroll system one might give an individual the authority to approve increases,
another the task of updating the computer and the third the responsibility to distribute funds to
employees. Without collusion between them, it would be difficult for any one of these
individuals to steal funds from the payroll system and hide his tracks. Unfortunately, in many
computer systems, too many separate functions have been computerised and often there is a
single clerk responsible for running the entire payroll process. In these situations, anyone who
has access to the application can take the opportunity to commit fraud. The most common
fraud tactics are:
• Entering fictitious transactions. Most frauds are committed by employees using the
system in the normal way to enter fictitious transactions. No special technical
knowledge is required and the employee relies on the fact that management
supervision of the process in weak.
• Modification of computer files. Normally requires a little more technical expertise as
this would involve, for example, the increase or reduction of amounts held on the
master file, which cannot be changed within the application without an appropriate
transaction (such as a payment).
• Unauthorised changes to programs. This type of fraud is usually limited to staff
with programming expertise. A common example is the skimming or salami
technique. In a payroll system this would entail deducting a small amount from each
individual salary cheque and adding the total to a select individual's payment. The
secret behind this technique is that employees are unlikely to notice a change in their
salary (PA YE and other deductions often cause regular variation in the total) and the
total payroll will balance (the total amount being paid is the same.)
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10. Security and Social Issues Section III
How does an organisation limit fraud? Experts suggest a three-pronged attack. Firstly the
organisation must stress the need for honesty and ethical behaviour in all business activities.
Managers must lead by example, new employees must be screened and staff training must
support this theme. The second concern is the level of opportunity in the organisation to
commit fraud. There must be strong internal controls, separation of duties, restricted access to
sensitive applications and constant management supervision. Audit trails are used to record
the origin of every transaction, and sequential numbering ensures that records cannot be
deleted or reports destroyed. Finally, where a case of fraud is discovered, action must be taken
against the offender. Many organisations prefer not to prosecute employees suspected of
fraudulent behaviour because of the negative publicity they will receive in the press. This in
itself encourages criminals to repeat the activity in their new working environment knowing
the likelihood of punishment is remote.
10.1.2 Unauthorised Data Access
Password protection is the most common method of protecting corporate data. Nevertheless,
fraudulent transactions are often carried out by unauthorised users who manage to gain access
to the corporate network by using the login details of another user. One way of achieving this
is through a terminal spoof - a simple yet effective approach to finding other user's
passwords. A terminal spoof is a program that runs on a machine and looks like the normal
login screen. Once a user has given his or her user-id and password, the terminal spoof will
record both on the local disk or server, give what looks like an authentic error message (such
as invalid password - please re-enter) and then passes control to the real login program. The
criminal will pick up the passwords later to gain access to the system masquerading as the
unfortunate victim.
Other criminals simply make use of an unattended computer that has been left on by a user
who has logged in to the network and then left the office. Time-out or screen-saver programs
with password protection provide a simple barrier to this approach In addition, locked doors
are a traditional means of excluding undesirable visitors.
Other dangers of which managers should be aware include the Trojan horse, in which code is
added to a program, which will activate under certain conditions. For example, a computer
consultant in Johannesburg had a client in Durban. He placed a Trojan horse in the payroll
program so that it would malfunction while processing the June payroll. They would fly him
down, all expenses paid, to fix the problem and stay for the Durban July horse race. Once this
had happened for the third time, another consultant was used who uncovered the offending
code.
Another risk is the Back-door technique. When programmers are building systems, they may
try to bypass all the access security procedures to speed up the development time. In some
cases, these "back doors" have not been removed and the programmer can gain illegal entry
into the production system.
10.1.3 Sabotage and Theft
When computers were the size of small houses and hidden in secure computer installations,
then theft of computer hardware was rare. Today, PCs are on most desks and in many cases
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Section III 10. Security and Social Issues
they have to be physically bolted to the table to prevent their disappearance. One famous case
of theft involved a laptop computer stolen from the back seat of a car in the USA in early
1991. On the hard disk was the master plan for Desert Storm, the details of how the United
States and her allies would attack Iraq.
Mobile computing devices are especially vulnerable to theft, and limiting of physical access
to equipment is the most effective first line of defence. Restrictions to entry can be based on
electronic locks, activated by means of magnetic disks or swipe cards, or on advanced
biometric devices that identify the individual based on characteristics such as fingerprints or
the pattern of the retina. (In each case, the security mechanism would obviously be linked to a
database containing details of authorised users.)
Another form of theft relates to the copying of programs and data resources in an
organisation. Obtaining customer lists together with the details of the amount and type of
business can obviously assist companies to encourage customers away from their competition.
Theft of software is a major problem in the PC world where users often make illegal copies of
the programs rather than purchase the package themselves - this practice is known as
software piracy. This type of theft is more difficult to identify, since the original product has
not physically disappeared as with the theft of computer hardware. Where software piracy is
discovered, the owner of the computer on which the software resides (often the employer) is
held to be legally responsible for the presence of pirated software.
The last category of computer theft covers the illegal use of computer time. In the past
computer operators were often caught processing work for third parties or users were doing
their own work at the office. Computer hackers spend their time searching for networks to
which they can gain access. Having breached the security controls, they often browse around
the databases in the installation but may not do any damage. In these instances, the only crime
they can be charged with is the theft of computer time.
70.2 Security Beyond the Organisation
10.2.1 Hackers and Firewalls
Hackers are users from outside the organisation, who penetrate a computer system usually
through its communication lines. Although some hackers are content merely to demonstrate
that they have bypassed network security, there is a high risk of malicious damage to data,
stealing of sensitive information (such as customers' credit card numbers) or entry of
fraudulent transactions by the hacker. Hackers may also instigate a denial-of-service attack,
in which a targeted web site is inundated with requests for information initiated by the hacker,
rendering it inaccessible for genuine business customers.
A firewall is an additional system that enforces access control policy between two networks,
especially between a corporate network and the Internet. The firewall monitors all external
communications, checks user authorisation and maintains a log of all attempts to access the
network. They can also be used to check for the presence of viruses, for the downloading of
unauthorised software, and to guard against denial-of-service attacks.
Discovering Information Systems 113
10. Security and Social Issues
Section III
HTTP Server
Internet Client
Serve r-si tie
tiro wall
Client-side
firewall
Figure 10-1. Diagram of a firewall (otn.oracle.com/products/ias/daily/Aug20.html)
Data which is in the process of being communicated is also vulnerable to eavesdropping.
Encryption, which scrambles data into an unreadable form, can be used to improve data
privacy and prevent any unauthorised changes to the message, as well as protecting the
confidentiality of data within the organisation.
10.2.2 Viruses
A computer virus is a program that invades a computer system, normally by residing in
corrupt files. The virus has the ability to replicate itself and so spread to other files and
computer systems. Some viruses are benign and merely advertise their presence, but others
corrupt the files they infect and even destroy entire databases.
There are three main types of viruses. The original viruses were mainly systems viruses. They
resided in the boot sector of a disk (the first place the computer looks when loading the
operating system) or in the operating system utilities. These viruses were usually easy to find
and clean. One problem was that they loaded into memory as soon as an infected machine
was switched on and could often hide themselves from the anti- viral software.
The next generation of viruses attached themselves to executable files. When an infected
program is run, the virus resides in memory and infects all new programs run until the system
is switched off. These viruses are difficult to counter, especially on a network as common
files are often infected. Even when the file server is cleared of infected programs, users have
copies on their personal hard drives, or a infected copy of the program in memory when the
virus check is performed on the server.
One area most users with which felt safe was the accessing of non-executable files such as
word processing documents. Unfortunately there are now a number of macro viruses that can
attach themselves to documents and spreadsheets. Even receiving a simple letter as an e-mail
attachment can infect your machine. Some of the more well known viruses include:
• Michelangelo. This virus infected many machines in the early months of 1992. The virus
was primed to activate on Michelango's birthday (6th March) and had the capability of
destroying all files on the hard disk of infected PC's. News of the virus made headlines
and many businessmen and home users rushed out to purchase programs to check and
clean viruses from their installations. On the day, some infections did occur but the main
winners were the vendors of virus detection software.
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• Stoned. A very common virus in the late 1980's it came in many forms, some harmless
while others corrupted files by attacking the directories and allocation tables. The main
theme of the virus was to legalise the smoking of cannabis and normally the message
"Your PC is now Stoned" would appear on the screen.
• Jerusalem. Deletes all programs that are run on Friday 13th.
• Concept. A macro virus, attached to word processing documents.
• EXEBUG. A nasty little bug that may corrupt your hard drive. This is a systems virus and
can infect the CMOS of your PC. Very difficult to find and eradicate as it uses "stealth"
technology to hide from virus checkers.
With increasing globalisation and interorganisational communications, viruses are able to
spread faster and further than ever before. Recent examples include Melissa, ILoveYou, and
the Nimda virus, which make use of multiple methods of transmission. The real mystery
about viruses is why they exist at all. Some experts suggest that computer hackers are
motivated by the challenge of "beating the system" by writing programs that can bypass virus
protection systems and take control of each individual machine. A more likely motive is to
induce computer users to purchase legal copies of software. The only real winners in the new
world of computer viruses are the companies selling computer software.
In the early 1980's the illegal copying of PC software, or software piracy was rife as there
was no real business advantage to purchasing the software (except a copy of the official
reference manual). Today it is estimated that about 50% of the PC software used in the USA
has been illegally copied and the situation in South Africa is likely to be worse. One of the
major motivations for buying software rather than copying from a friend is that the shrink-
wrapped product is guaranteed to be virus free.
The best line of defence against viruses is the regular use of up-to-date anti-virus software,
which will scan files for viruses and remove them if found.
10.3 Operational Problems and Errors
Computers are often seen as "super humans" in that they can perform their tasks at high speed
and great accuracy. However the computer has its own, very specific weaknesses.
10.3.1 Dependency
Dependency may become a problem at two levels. Firstly, users of on-line, real-time systems
are often totally reliant on the computer to perform their tasks. For example, visualise a busy
Saturday at the local Pick 'n Pay supermarket when the back office computer malfunctions.
All the point of sale terminals are linked to this machine to obtain price and other information
and until the problem is fixed, no sales can be processed. Not a pleasant situation for shoppers
and store managers alike. All organisations reliant on their computer to perform critical
business activities must have a contingency plan to cover such emergencies, from the simple
malfunction of a unit of hardware to a major disaster such as a fire in the computer
installation.
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10. Security and Social Issues Section III
At an individual level, employees who are accustomed to using a computer as a source of
information, may lose confidence in their own judgement or decision-making abilities. When
the computer is offline then all business activities grind to a halt, even though many of those
processes could have continued based on principles and procedures that are not power-
dependent !
10.3.2 Illogical Processes
Most conventional computer programs are made up of simple commands to instruct the
machine (expert systems being one exception). When a computer error occurs, it could be as a
result of hardware malfunction or the corruption of data. However this seldom results in an
incorrect report or enquiry as the hardware and software are designed to detect this loss of
integrity and provide an appropriate response (stop processing or generate an error message).
Computers do not make calculation errors or read the incorrect data. But we have all heard
stories of customers receiving telephone bills for outrageous (and incorrect) amounts and
banks transferring amounts to the wrong accounts. These problems invariably originate from
errors made by computer users or errors in the programs written to control the process. While
humans make mistakes, sometimes on a regular basis, they have the advantage of working
intelligently (although this is not always obvious). A clerk in a manual debtors system will
probably realise there is an error when the telephone bill is over Rl, 000,000 and will check
the client's detailed records before dispatching the account. The computer blindly follows the
instructions in the program. However we can provide the computer with some sensitivity to
problems by adding reasonability checks. For example it could highlight all amounts that
appear to be too large (or small) in an exception report for the supervisor to check prior to
distribution.
The bottom line is that the information provided by a computer should be more accurate and
reliable than output from a manual system, but much depends on the expertise of users and
computer professionals in the development and operation of the system. One classic example
of a computer error occurred when one of the authors was working in the computer
department of a large oil company. A colleague made a change to the layout of the customer
statement to add a place for comments to be included, and tested the change by putting in a
"Happy Christmas and Prosperous New Year" message. Needless to say he forgot to remove
the message for the next monthly run and 25,000 customers were wished "Happy Christmas"
in the middle of July.
In a number of studies focused on threats to computer systems, the largest percentage of
financial losses were not from computer crime (20%), disasters (15%) or sabotage (15%) but
from employee ignorance or negligence (50%). Management is often focused on external
threats and natural disasters but the threat is from within. The recommendations from this
research highlighted the fact that motivated, well-trained and supervised employees will go a
long way towards reducing computer problems in the work place.
70.4 Computer Monitoring and Privacy
One of the major advantages of commercial computers is that given a large quantity of data
about the organisation's business activities, it can then analyse the data from many different
perspectives and provide management with valuable information as to the status of the
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Section III 10. Security and Social Issues
operation. If people are part of this system, either as customers, employees or even operators,
the computer can use the information at its disposal to report on the activities and
performance of each individual. The question is, how far can this process go before it
becomes an invasion of privacy?
10.4.1 Computer Monitoring
As transactions are processed in a computer system, the program could store the code of the
operator in the transaction to record who performed the activity. At a later date we may want
to check on some aspect of the transaction and could check which operator was on duty at the
terminal. We could also take all the transactions over the month and summarise them by
operator code to evaluate the amount of work done by each operator. We could also analyse
the number of mistakes, and the times when operators logged into the system and logged out.
With the introduction of workflow systems where documents are scanned into the system and
routed to various workers, there is some justification for monitoring the pace and progress of
activity on the network. However there are negative aspects as well. Monitoring can be
stressful to certain individuals and there is a school of thought that suggests that workers who
are being monitored change their work patterns and work quicker rather than better (issues
such as customer consideration may be ignored as they appear to waste valuable time).
This all sounds much like George Orwell's "1984", a book about a future world where every
thought and action were watched by Big Brother. Currently, one of the major issues of
conflict between workers and management in the USA is whether supervisors should be
allowed to read e-mail addressed to their subordinates. When e-mail is transmitted across the
country, its privacy is protected by law, but within a business, e-mail is held to be the property
of the employer, since it was created during the employer's time and using the employer's
resources.
10.4.2 Invasion of Privacy
The other side of the coin is where organisations obtain information about an individual and
use it for commercial advantage. You may be surprised to find out how much information
about you is stored in computers around the country. Your school and university will hold a
lot of personal information. You will have applied for a job or two, opened a bank account,
purchased a house and applied for water and electricity supplies. You will have a few
insurance policies, be seeing a doctor and dentist, have an account at a number of stores and
own both a regular and cell phone. All these organisations will have information about you,
and some of this information could be classed as sensitive such as your overdrawn bank
account and the time you were caught for driving under the influence (mentioned on your
school report).
This information has value. Direct mail businesses would like to post you catalogues and
flyers detailing their latest products; and credit bureaux can use the data to assess your credit
standing. More sinisterly, bureaux specialising in computer data matching are buying data
from many sources to create a complex profile for each individual.
Most countries now have strict privacy laws to protect their citizens. For example the Federal
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10. Security and Social Issues Section III
Privacy Act in the USA states that:
Individuals are free to determine what information is being held by an organisation
They can prevent the use or distribution of their information to other organisations
without their consent
They can view, obtain copies and correct their information
Information can be collected and used only for necessary and useful purposes
Information must be kept current and accurate
Safeguards must be provided to ensure the data is secure and not misused
Individuals can institute claims for damages they suffer as a result of wilful or
unintentional violations of these rights
Similar legislation was introduced in South Africa in 2002, giving all citizens the right to
know what data has been stored about them, what it is being used for, and to insist that
incorrect data be rectified.
Although many issues have been resolved and the rights entrenched in law, others are very
topical, controversial and as yet undecided. One example is the debate as to whether there
should be censorship on the Internet. Should the network be an open medium for the free
exchange of ideas and information? Or should legislators take responsibility to regulate
content and activities such as child pornography. The debate continues.
10.5 Computers and Unemployment
James Martin calculated that computer processing was about on a par with manual processing
in terms of cost performance in 1978. Since then computer processors have doubled in power
every two years with little or no increase in cost. If the motor industry had advanced at the
same speed as computers over the past 50 years, a Rolls Royce would cost less than RIO and
run for a year on a single tank of fuel. Obviously these advances have provided business with
cheap, reliable processing power but they have also begun to impact on employment levels.
Early growth in computer processing had little effect on jobs. The introduction of computer
systems called for new skills as large amounts of data needed to be captured. While some of
the repetitive transaction processing was now automated, clerical workers could now
supervise and control the processing cycle. Computers were hailed as machines to take the
drudgery out of work and in most cases this was so.
With today's widespread use of computers, there are a number of changes to employment
patterns that are credited to the computer revolution.
As anticipated, the clerical workers in many companies are gradually becoming knowledge
workers, requiring new skills to operate and manipulate computerised applications. The
numbers of these employees has shrunk over time as computer applications propagate
throughout the organisation.
The number of blue-collar workers (employees in the manufacturing function) is falling. In
some cases this is a result of improved processes and productivity but the impact of
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Section III 10. Security and Social Issues
automation and the introduction of robotic assembly is also a factor.
The impact of computerisation is most felt in the area of middle management when
sophisticated MIS and DSS systems have provided top management with easy access to
information without the overhead of layers of supervisors and managers. The outcome of this
change is a sharp reduction in the layers of management in most organisations and the arrival
of large numbers of middle aged managers at the unemployment queues.
Opinions are mixed about the long-term effects of computerisation on employment. Some
experts predict that job losses from technological advances are always offset by increased
demand for skills in other areas. The jobs are there but some individuals may need re-training.
The other side of the coin is that computer technology can improve productivity while
reducing costs, and staff is often the major cost to the organisation. The new reality may be
that more and more people will lose their jobs to computers as corporations fight to remain
competitive.
10.6 South African Perspective
Spam is the equivalent of junk mail sent via the internet: electronic messages are sent
automatically to computer-generated e-mail lists. The recently promulgated Electronic
Communications and Transactions (ECT) Act of 2002 protects individuals against unwanted
spam, by requiring any company that sends unsolicited commercial communications to
provide the recipient with the option of being removed from the mailing list, and to disclose
the source from which the his or her details were obtained.
During January 2003 the first charge was laid in terms of this section of the Act, against a
marketing company which continued to send unsolicited emails after having been requested
not to do so. Companies or persons found guilty of such an offence are liable for a fine or
imprisonment for up to 12 months, but the cost to the taxpayer may be disproportionately
high. In this case, since the charge was laid at a Johannesburg police station, and the
marketing company is based in Cape Town, a search and seizure warrant would have to be
issued in Johannesburg and sent to Cape Town for approval by a Cape Town magistrate, after
which a member of the SAPS would carry out the warrant and obtain a copy of the company' s
database to be used as evidence. Although a successful conviction may act as a deterrent to
other South African companies in the future, the global nature of the internet makes it
virtually impossible to control electronic communications through legislation.
10.7 Beyond the Basics
Biometrics is the technique of electronically measuring a physical characteristic of an
individual and automatically comparing that measurement with an equivalent value stored in a
database, in order to identify the individual. Among the many physical characteristics that
have been used for biometric measurement, the three that have given the most consistently
successful results are retinal scanning, iris scanning and finger imaging.
Retinal scanning involves bouncing a beam of light off the back of the eyeball, using a
scanning device that rotates six times per second to build up a map of the blood vessels that
are present. The information is then digitised and stored in an easily retrievable database.
Discovering Information Systems 119
10. Security and Social Issues Section III
Although this technology requires close proximity of the individual to the scanning device, it
provides a unique and stable method of identification. Iris scanning measures the arrangement
of structures within the coloured circle that surrounds the pupil of the eye. It also provides a
unique and permanent template, but is more demanding than other methods in term of
equipment cost and memory requirements. Finger imaging is the 21st century implementation
of the fingerprints that have been in use for decades, and is based on the generation of a
unique byte code from the scanned image of a fingerprint. This technology still requires
physical contact with the scanning equipment, and the results can be distorted by dirt or skin
damage.
10.8 Exercises
10.8.1 Viruses
• The Nimda worm spread rapidly across computer networks during September 200 1 .
Use the internet to find out three methods that it uses to infect computer systems.
• Suggest three precautions that you could take to reduce the risk of your PC becoming
infected with a virus.
• Read the email message that follows, and then use the internet to find out whether
such a virus actually exists.
From:
Subject: Urgent - Virus alert
Virus Planet !
To those who are using handphone ! !
Dear all mobile phone's owners,
ATTENTION! ! ! NOW THERE IS A VIRUS ON MOBILE PHONE SYSTEM.
All mobile phone in DIGITAL system can be infected by this virus.
If you receive a phone call and your phone display "UNAVAILABLE"
on the screen (for most of digital mobile phones with a function
to display in-coming call telephone number), DON'T ANSWER THE
CALL. END THE CALL IMMEDIATELY!!! BECAUSE IF YOU ANSWER THE CALL,
YOUR PHONE WILL BE INFECTED BY THIS VIRUS.
This virus will erase all IMIE and IMSI information from both your
phone and your SIM card which will make your phone unable to
connect with the telephone network. You will have to buy a new
phone .
This information has been confirmed by both Motorola and Nokia.
For more information, please visit Motorola or Nokia web sites:
http : / /www . mot . com
http : //www . nokia . com/
There are over 3 million mobile phone being infected by this virus
1 20 Discovering Information Systems
Section III 10. Security and Social Issues
in USA now.
You can also check this news in CNN web site: http://www.cnn.com
Discovering Information Systems 121
Case Study Section III
CASE STUDY: CREAM ADVERTISING
Cream is a large and well-established advertising company, with corporate clients in all the
major South African cities. Over the last decade, Cream has developed a reputation for the
creation of avant-garde and witty advertising campaigns, predominantly on television and in
glossy magazines, and has scooped several prestigious national awards. Much of their success
is ascribed to the diversity of talents and personalities within the company, and a strong ethos
of teamwork. A lot of time is spent in meetings and informal discussions between staff, and
the pervading culture within the organisation is that work should be not only challenging but
also fun.
Information technology is used to support various separate business functions:
• Accounting and administration, including the general ledger, accounts payable and
receivable, and payroll.
• Graphic design for the development of new conceptual material.
• Word processing and presentation software for writing copy and making presentations
to clients
• E-mail for communications and internet browsing to keep up with advertising trends.
Cream does not have an in-house IS department, and relies on the support provided by
vendors and outside consultants to maintain their systems and solve any computer-related
problems.
A brief overview of their business activities is as follows:
•
The general manager, Jade Smith, contacts existing client by phone at least once a month
to check that they are happy with the performance of their current campaigns, and perhaps
make suggestions for future changes to content or media.
All members of staff listen to industry gossip, and if a competitor's advertising campaign
appears to be badly received, Jade is informed and decides whether to contact the client to
market Cream instead. If so, she sets up an appointment for the marketing manager, Tim
Mabusa, to give a standard presentation showing examples of previous work. Tim also
provides a glossy brochure detailing the expertise and abilities within the firm, but his
enthusiastic personality is a vital ingredient of the sales talk.
When a new campaign is initiated, Jade will appoint one of her senior staff as project
manager, and the two of them will meet with the client to discuss the form that the
campaign should take (content, media, etc), and provide an initial (estimated) quotation.
In many cases this meeting involves travel to other cities, which adds to costs and
seriously impacts their availability for dealing with other business issues.
A fee of 20% of the initial quote is payable before any further work on a new campaign is
undertaken. A project team consisting of the project manager, a graphic designer and a
copywriter will then work closely together to create several alternative ad outlines. These
122 Discovering Information Systems
Section III Case Study
are presented to the client for discussion and possible reworking before the final quote is
submitted and production begins on the advertisement.
• Cream take care of all the liaison with publication media, and confirm to the client the
periods and costs involved. The actual account for publication or broadcasting is
submitted directly to the client, and Cream is not involved in the client's financial
transactions other than the money charged by themselves for work done. Payment of the
final quoted amount less the initial fee is due within 30 days of completion and invoicing.
As the business has grown, so more and more time is being spent on travel, telephone calls
and faxes. A lot of coordination is needed to keep track of the various elements of each
campaign, and make sure that actual advertising material, publication arrangements and
accounting are all being attended to. Holdups frequently occur because the initial 20% fee has
not yet been debited, or else it has been received but the project team have not been informed
that they can proceed; and several TV ads have received unsatisfactory broadcast times
because bookings were made late. Staff are tired rather than stimulated, and Jade is concerned
that the quality of their work will be affected. She is wondering whether the introduction of
additional technology to support the business processes would free her staff to focus more on
their creative abilities.
(a) Give practical examples of how information systems could be used to support the
business at each of the management levels.
(b) If you were Jade Smith, what business strategy would you select (low-cost,
differentiation, or niche marketing) and why? How could IS be used to support this
strategy?
(c) What opportunities would there be for the use of groupware, both within and beyond the
company?
(d) In what ways could the implementation of e-commerce replace or enhance the existing
business activities of Cream?
(e) A network infrastructure that supports e-commerce also exposes the organisation to added
security risks. Suggest ways in which these risks could be minimised.
Discovering Information Systems 123
IS Management Section IV
Section IV: IS Management
Since the birth of commercial computing, organisations have been developing computer
applications to meet the needs of their users. Initially this process was almost entirely
machine orientated since the high costs of computer hardware made it necessary to maximise
the usage of this scarce resource.
Initially computers were used as sophisticated record keeping devices. As their price
performance became more attractive so more and more secondary applications were found.
Gradually each organisation's portfolio of computer applications has grown to the point that
many could not function without the use of this electronic device. Organisations are using
Information Systems to boost competitiveness and growth.
This transition has also seen the evolution of information architectures. Today's information
processing environments tend to be integrated, decentralised and highly complex. They
require detailed planning as to what hardware infrastructure should be established and which
new applications should be developed. They require high quality systems to be developed as
the maintenance load in some organisations is threatening to draw on all the resources of the
IS department.
Advances in computer technology have resulted in computers becoming thousands of times
faster, cheaper and therefore more productive than machines of the late 1950's. Unfortunately
improvements achieved in the development of applications software have not kept pace, with
the result that developing and maintaining in-house applications has become the major cost
facing today's IS departments.
IS development projects require careful planning and the use of sophisticated tools with
which to build new applications, and management techniques to ensure systems are delivered
on time, within budget and to the user's expectations. The successful introduction of new
systems also depends on the handling of change management within the organisation and the
establishment of reliable procedures both for routine business activities and for coping with
unexpected occurrences.
124 Discovering Information Systems
Section IV 11. IS Planning and Acquisition
11. IS Planning & Acquisition
We know why organisations acquire new computer systems. In most instances computers are
cheaper and more efficient than people when it comes to performing common, well defined
tasks such as deciding when stock items should be reordered or generating customer
statements. And as the productivity gap widens with each new advance in computer
technology, new and innovative ways are being found to reduce costs through automation.
The question is "how does an organisation recognise the need for a new computer system?"
Forces that highlight the need for change could come from the business environment (such as
increased competition or new government regulations) or from within the business itself (for
example where growth is beyond the capacity of the current system or new products are
identified). Increasingly opportunities to automate arise through the introduction of new and
innovative technology which can provide major cost reductions, improved management
information and better service to customers. In most medium to large organisations there is a
formal strategic planning process; and the new directions and changes identified in the 3 to 5
year business plan will enable the organisation to identify the computer systems required to
support these applications in the future.
Once the need for a new system has been identified, plans must be developed to ensure that
the new system can be successfully integrated with existing business processes, and that it
will provide an acceptable return on investment for the organisation. Finally, effective project
management is essential if systems are to be produced that correctly fulfil the requirements of
their users without exceeding the constraints of time and budget.
/ /. / Frameworks for Analysing Information Systems
There are many frameworks for analysing and studying information systems. Many of the
commercially inspired frameworks are tied to a specific system methodology: they are very
specific, often proprietary, approaches to analysing information needs, designing and
developing information systems that address these needs. In addition, there have been many
academic frameworks developed, each suitable for specific types of analysis e.g. strategic
planning, comparative analysis, historical analysis, etc.
To give you an idea of these frameworks, we give you three examples.
11.1.1 Value chain analysis
In value chain analysis, the organisation is seen as a large input-output system, in which the
inputs are the raw materials or services brought into the organisation, which are processed in
some way, marketed and sold as outputs. Each point of this chain is analysed to uncover
opportunities where value can be added or costs reduced. Although the complete model of the
value chain usually includes both primary and support activities, the greatest level of return
can be expected through the implementation of IS within the primary activities.
• Inbound logistics include the receiving, warehousing, and inventory control of input
materials.
Discovering Information Systems 125
11. IS Planning and Acquisition Section IV
• Operations are the value-creating activities that transform the inputs into the final
product.
• Outbound logistics are the activities required to get the finished product to the
customer, including warehousing, order fulfillment, etc.
• Marketing & Sales are those activities associated with getting buyers to purchase the
product, including channel selection, advertising, pricing, etc.
• Service activities are those that maintain and enhance the product's value including
customer support, repair services, etc.
Inbound „ ,. Outbound Marketing
T > Operations > T > „ e .
Logistics r Logistics & Sales
Figure 11-1. Primary activities within the value chain
11.1.2 The Zachman Framework
Zachman developed a framework aimed at a more systematic delivery of information
systems, modelled loosely on the way buildings are constructed from an architectural point of
view. According to Zachman, information systems need to be considered from six different
perspectives (or dimensions).
• Data: which data entities do you want to capture and what are the relationships
between these entities?
• Function: which (business) functions need to be addressed and which arguments does
each function have?
• Network: which nodes need to be supported and what links exist between them?
• People: who are your agents and what are their tasks or work?
• Time, when do things happen and to which cycles do they conform?
• Motivation: what are the ends or goals and by what means will you get there?
Each of these dimensions is then examined at a number of different levels, to identify the
system requirements and how they can best be implemented.
11.1.3 Strategic Importance Grid
The strategic importance grid looks at the entire information systems portfolio of an
organisation i.e. all the systems currently in operation as well as the future systems currently
under development or being planned. The critical focus of this framework is the assessment of
whether a significant portion of an organisation's systems is of a strategic nature and
classifies the organisation accordingly into one of four possible categories on the IS strategic
importance grid as shown in figure 1 1-2.
1 26 Discovering Information Systems
Section IV
11. IS Planning and Acquisition
Systems Currently
in Operation
Systems under
Development/
Being Planned
Predominantly of a
Strategic Nature
STRATEGIC
TURN-AROUND
Predominantly of an
Operational Nature
FACTORY
SUPPORT
Figure 11-2: Strategic importance grid
The main use of this table is to assess the importance of the IS strategic planning in the
overall strategic business plan. It can also be of use when doing strategic competitor analysis
or when assessing significant shifts in IT budgets. Try to find an example of a South African
company for each of the four categories. As you try to place these examples, you will notice
that the boundaries between the cells are not definitive: some companies will occupy
boundary positions between cells whereas others will fit a certain category almost perfectly.
11.2 IS Planning
The various components of an organisation's information systems (hardware, software,
databases, networks, and people) need to be successfully integrated in order to provide the
right information at the right place and time. This is not going to happen by accident. An IS
architecture is needed to define the IS resources that will be used to support the business
strategy, and the standards that should be adhered to in order to ensure compatibility within
the system.
The starting point for IS planning should be the clear identification of the application needs of
the business, based on the information that is required by management. The activities that are
managed by the IS department, such as the prioritising and scheduling of system development
projects, must be in line with overall business goals. Alternative software products and
acquisition options need to be evaluated before a decision can be made about the hardware
and operating system that would be most appropriate.
Computer hardware should then be assessed on the basis of its compatibility with existing and
future systems, its expandability and reliability. Other important issues include the availability
of technical support, estimation of operating costs, and the financing method (e.g. leasing or
buying) that is to be used.
11.2.1 Cost-benefit analysis
Cost-benefit analysis can be used to assess and prioritise new system development projects,
by measuring the financial impact of proposed systems. Tangible benefits could include
reduced inventory and administration costs, higher processing volumes, reduction of bad
debts and improved cash flow. Intangible benefits such as improved customer satisfaction and
better decision-making are more difficult to measure, but could be of significant value.
Discovering Information Systems
127
11. IS Planning and Acquisition Section IV
Typical costs that have to be considered in evaluating projects are
• Development costs, including staff training and conversion from the previous system
• Equipment costs, including space and air-conditioning requirements
• Operating costs such as staffing, insurance and power.
The reason for undertaking a cost-benefit analysis is to ensure that over the lifetime of the
system, its benefits will exceed its costs, even though costs are likely to exceed benefits
during the initial stages. The calculation must take into account the time- value of money (net
present value) when determining the break-even point for the system, since interest would be
earned (or saved) on the capital that will be invested in the project.
11.2.2 Funding of IS
The are three basic options available for the funding of an organisation' s information systems :
as an unallocated cost centre, as a cost centre, or as a profit centre.
The traditional model of an unallocated cost centre means that IS is regarded as an
organisational cost, for which an annual budget is allocated in order to meet the costs of
system development and maintenance. Other departments are likely to have little influence
over the spending of the IS budget, the prioritising of projects and the standard of service that
is delivered.
When the IS department operates as an allocated cost centre, then internal accounting is used
to allocate IS costs to the departments using them. This makes it easier to identify areas of
demand within the organisation, and may reduce the number of requests for (unnecessary)
projects.
A profit centre approach means that the IS department must compete with outside vendors in
providing IS services to the organisation. This often results in increased efficiency of the IS
department, but may reduce the time spent on less profitable developmental work, reducing
the ability to provide innovative and potentially strategic IS capabilities.
1 1.3 Software Acquisition Options
11.3.1 In-house development
Most large organisations have their own IS department, which is responsible for the
development and support of the computer systems used to support the company's strategic
goals. The methods commonly used during in-house development are covered in detail in the
next chapter. However, this approach depends on highly skilled employees, and because of
the time and cost involved, it often results in a backlog of projects awaiting development. If
IS staff do not have the necessary technical expertise, or are too busy to attend to low priority
projects, then alternative system development methods may need to be considered.
11.3.2 Commercial packages
The acquisition of off-the-shelf software packages provides a low-cost alternative to in-house
128 Discovering Information Systems
Section IV 11. IS Planning and Acquisition
development, since the cost of development has been spread over a number of users. The
software can be examined and tested prior to purchase, minimising the risk involved, and user
training and support are often commercially available. Even if some customisation is required,
a package can be installed in a very much shorter time frame than if an equivalent system is
developed from scratch. In general, if a suitable package is available, then this is the best
option for acquisition of software.
11.3.3 Outsourcing
Outsourcing involves the purchasing of a service, in this case software development, from
another company. With rapid changes in technology and high turnover rates for IS staff, it
becomes increasingly difficult to maintain high levels of expertise in-house. Outsourcing
allows an organisation to focus on its core competencies, while benefiting from the expertise
and economies of scale that can be provided by the outsourcing company. Contracts and
service level agreements need to be clearly defined, and in many cases organisations will
outsource only their more general systems, while retaining control over strategic projects. In
this case, additional contract staff can be used to provide skills that are not available
internally.
A recent trend is towards the use of application service providers (ASPs), who maintain a
range of software programs on their own computers. These are made available to customers
via a web interface, and are a cost-effective solution for the provision of software that is used
infrequently or from varying locations. The principle underlying this approach is that just as a
company would not consider producing electricity privately to meet its own needs, but finds it
easier to pay a supplier based on usage, so the company can pay for the use of applications
which have been developed, installed and maintained by an ASP.
11.3.4 End-user computing
With the growth of computer literacy in the workplace, plus decreased costs of computer
hardware and user-friendly development tools, end-user computing has become an important
factor in system development. Faced with frustrating backlogs in the IS department, or
inspired by the opportunities presented by new technologies, an increasing number of users
are attempting to develop their own systems. The majority of user-developed applications
tend to be personal or departmental in function, and often do not adhere to organisational
standards. Data validation and security may be poor, backup and recovery procedures are
often missing, and lack of documentation means that if the developer leaves the organisation,
then the system is likely to fall into disuse. In response to these concerns, user support centres
may be established to provide training and assistance for users.
11.4 Project Management
Project management differs from general business management in that a project has a
beginning and an end, between which a definable set of activities must occur. Most projects
are once-off efforts, so previous experience is likely to be limited, and the high degree of
interaction between participants and tasks adds to project complexity. In order to meet these
challenges, special project management tools have been developed to assist with project
planning, resource allocation, scheduling and review.
Discovering Information Systems 129
11. IS Planning and Acquisition
Section IV
Widgets-R-Us
2002
January
February
March
April
May
June
July
All Projects
Project A
Task A1
TaskA2
Task A3
24
5/4
TaskA*
Project B
Task B1
Task B2
:
i
Task B3
-.1. '>
Figure 11-3. Example of a Gantt chart
The first task of the project manager is to define the scope of the project, the tasks to be
accomplished and the order in which they should be done. This information can be
represented using a Gantt chart (see Figure 11-3), which also reflects the start and end dates
of major tasks and the staff involved. Dependencies between tasks then need to be identified,
since any hold-up at a critical point might affect the completion time of the project as a whole.
A network diagram or Pert chart shows the minimum and maximum time that might be
needed for each task, as well as which tasks must be completed in sequence and which can be
addressed in parallel, so that the impact of delays can be accurately assessed. Risk assessment
techniques can be used to identify risk factors and implement strategies for minimising the
potential problems associated with systems involving complex technology or where user
requirements are not clearly defined.
The progress of a project must be monitored throughout its lifespan, usually on the basis of
deliverables submitted at the end of each phase. Comparisons with the budgeted time and cost
are made at frequent intervals, so that problems can be identified and corrected (or the project
abandoned) as early as possible.
Another important element in project management is the acquisition and training of staff and
the development of relationships both within the team and with the future users of the system.
This can be supported through the organisation's intranet together with the effective use of
groupware applications such as email and electronic meeting support.
It should be apparent from these examples that more than one software tool is required to
provide the different perspectives needed for effective project management. Many of the same
tools can also be used to improve general business efficiency, for example in the periodic
scheduling of jobs and employees by operations managers.
130
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Section IV 11. IS Planning and Acquisition
1 1.5 People Aspects of Systems Development
The systems development process will involve IS professionals, management, end users and
outside vendors.
Management. Decisions as to which computer systems are to be developed and the allocation
of IS resources to current projects must be made by general management with advice from the
IS department. One way this can be achieved is to form a computer steering committee with
representatives from top management, managers of the various business functions and the IS
manager. The chief information officer will manage IS resources (including staff), liaise with
top management and advise on strategic opportunities.
Historically IS developers have a poor record in terms of delivery of new computer systems
on time and within budget. The appointment of a project manager (who may be a systems
analyst with the required project management skills) will help to keep the project on schedule.
IS professionals. The systems analyst plays the part of an intermediary in the development
process, providing the link between users and the programmers and technicians who will
build the system. The analyst's role is to develop the user requirement and detailed design
specifications and to provide continuity and management support throughout the project. He
or she must therefore have a strong understanding of the business together with the required
technical skills. In addition the analyst must possess the management and behavioural skills to
supervise and communicate with people.
In many organisations the analyst's role has been split into that of the business analyst,
normally an individual with a strong commercial background who will perform the analysis
function, and the systems designer, a technical analyst who will develop the detailed
specifications of the system.
Programmers work from the detailed program specifications developed by the analyst, and
code and test the required program modules.
In large organisations there are individuals in technical roles who will provide support for
development projects in the design and implementation stages. For example the database
administration function will provide expertise in designing and construction of the database,
network specialists will assist in the design and implementation of local or wide area
communications, and the web administrator will be responsible for the development, delivery
and integration of web resources.
Internal auditors will be needed to review the controls of the system.
End-users. These are the people who will ultimately use the new system. In the past they
were largely ignored once the analyst felt their requirements were known. Modern practice
dictates that users be involved in every stage of the development project. This involvement
has two main objectives. Firstly the user can define what he wants and give details of the user
interface. In addition user involvement breaks down resistance to change. Making the user
part of the development team ensures a commitment to the successful implementation of the
application.
Discovering Information Systems 131
11. IS Planning and Acquisition Section IV
In many cases, end-users are also assuming a role as system developers, although the
responsibility for network, database and hardware management is likely to remain under the
control of a centralised IS department.
Outside vendors. Outside organisations may be providing hardware, software or their
consulting expertise. Many organisations use outside contractors as analysts or programmers
to help in development projects. Contractors are useful when an organisation lacks technical
skills in an area or has a shortage of staff. The problem with contract staff is that the
knowledge and skills developed during the project can disappear when the contractor leaves.
Adequate documentation and training of in-house personnel are the obvious solutions.
11.6 South African Perspective
Clover Dairies, the oldest and largest dairy company in South Africa with over 6500
employees and a turnover exceeding R3 billion, distributes its products across a widespread
customer base. Early in 2003 they invested in the Heat customer service system to support
centralised information requests, order processing, claim handling, invoice and credit note
queries, complaints, account administration and customer requests, as well as conducting
customer and product surveys. According to the ICT systems manager at Clover, the decision
to buy this particular product "was based on several criteria, including cost-effectiveness,
product-effectiveness, the strategic importance of the product to Clover, its functional fit, and
the levels of service and support available". Heat will also be integrated into Clover's existing
business planning and control systems as well as its telephony system, and will be accessible
via a web interface over its network connection.
11.7 Beyond the Basics
There are various issues to be considered when planning for e-commerce applications.
• Rather than the traditional cost-benefit approach, web initiatives may be seen as a
strategic investment to be used as a platform for future business activities.
• As part of the overall information architecture of the organisation, a top-level decision
must be made as to whether the entire site will be developed and maintained as a
single project (either in-house or outsourced), or whether only core functions will be
initially planned and developed, allowing departments to extend it later as required.
• An extended group of users needs to be considered in planning a web-based system:
surfers who are browsing the Web, customers who wish to make online purchases,
suppliers and recipients. Many of these are not usually regarded as direct users of
traditional IS applications. Accessibility issues are also raised, to allow for the
possibility of external users who are physically or mentally handicapped.
• Even though the benefits resulting from a website are difficult to quantify, the
effectiveness of the site in fulfilling its purpose must be evaluated in the same way as
any other IT investment, to ensure that business requirements are being met and
problems are identified.
132 Discovering Information Systems
Section IV 11. IS Planning and Acquisition
11.8 Exercises
11.8.1 Value chain
For each stage of the (primary) value chain, how could IS be used to cut costs or add value to
business activities?
11.8.2 Software acquisition options
The different software acquisition options available to organisations include in-house
development, commercial packages, outsourcing and end-user development. Compare these
three approaches in terms of each of the following factors:
• Cost control: how well can costs be estimated at the start of a project, and how
successfully can budgets be enforced?
• Availability of expertise: how likely are you to run into difficulties if the project
turns out to be more complex than was initially envisaged?
• Quality of the final system: can you be sure that the final system will meet your
requirements, and will do the job without errors?
• Documentation and training: will these be available when the system is first used,
and at later stages if required (e.g. for new staff)
• Maintenance: how easy will it be to make changes to the system in five years time?
In ten years time? What if you need to integrate other systems with this one?
Discovering Information Systems 133
12. System Development Section IV
12. System Development
This chapter will provide you with an overview of the systems development process. First we
describe in detail the traditional Systems Development Life Cycle (SDLC), encompassing
the stages through which each system should pass, from the initial survey to hand-over of the
completed system.
Pressure for rapid development and future maintainability of systems has resulted in a number
of alternative approaches to systems development, ranging from development by end-users, to
the incorporation of formal methods to improve the quality and efficiency of the development
process.
12. 1 Systems Development Life Cycle (SDLC)
Systems development could be seen as the simple process of writing programs to solve the
needs of the user. Unfortunately the user knows what he wants but has no technical expertise
while the programmer understands the computer but not the user environment. This
communication gap between the customer and the service provider must be handled by an
intermediary, the systems analyst. Broadly speaking therefore the systems analyst translates
user's needs into detailed specifications for implementation by the programmer.
Over the years the software manufacturing process has become more formalised:
"The basic idea of the systems development life cycle is that there is a well
defined process by which an application is conceived, developed and
implemented. The life cycle gives structure to a creative process. In order to
manage and control the development effort, it is necessary to know what should
have been done, what has been done, and what has yet to be accomplished. The
phases in the systems development life cycle provide a basis for management
and control because they define segments of the workflow which can be
identified for managerial purposes and specify the documents or other
deliverables to be produced in each phase." [Davis and Olson, 1985]
The number of stages and names to describe those stages differ slightly between
organisations; but the SDLC normally covers the activities shown in figure 12-1, each with a
primary purpose.
12.1.1 Preliminary Investigation
The preliminary investigation is carried out to determine the scope and objectives of the
new system and to investigate whether there is a feasible solution. New applications normally
originate from end-user requests and are weighed against the other requests for IS resources
before approval to develop the system is granted. At this stage an analyst or small project
team is authorised to investigate the real potential of the new application. During this brief
study the analyst must investigate the problem and the existing system sufficiently to be able
to identify the true extent and purpose of the new application.
In order to ensure that the new system would be of greater benefit to the organisation than
134 Discovering Information Systems
Section IV
12. System Development
other competing requests for proposals, a feasibility study must be performed covering the
following three major areas:
• Economic feasibility to measure the costs and benefits of the new system.
• Technical feasibility to ensure that the organisation has sufficient hardware, software
and personnel resources to develop and support the proposed system.
• Operational feasibility, the willingness and ability of management, users and
Information Systems staff in the organisation to build and use the proposed system
PRELIMINARY INVESTIGATION
Understand the problem and test for feasibility
ANALYSIS
Investigation to determine what the user requires and
identify the most cost-effective solution
DESIGN
Develop specification of how the new system will run
BUILDING
Build or program the new system
IMPLEMENTATION
Convert to the new system
MAINTENANCE
Ongoing enhancement and support of the new system
Figure 12-1: Systems Development Process
Issues such as the size and complexity of the new system and the skills and availability of
user and IS staff, will determine the level of potential risk to the organisation in developing
the system.
The output from this preliminary investigation is a statement of scope and objectives (often
termed the project charter) together with a feasibility report. This document is submitted to
management where a decision is made as to whether or not the development project should
continue.
12.1.2 Systems Analysis
In this stage the analyst investigates the needs of the user and develops a conceptual solution
to the problem. One human failing we all tend to exhibit is to rush into proposing solutions
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before we fully understand the problem we are trying to solve. It is therefore important for the
analyst to develop a broad, conceptual solution to the problem (what needs to be done) prior
to launching into the detailed physical design where we specify how the system will work.
In the past analysis tended to be very much a pragmatic affair with success more dependent
on the experience and capabilities of the analyst than on any formalised approach. The
analysis phase should include the following discrete steps:
• Understand how the existing system operates. This information can be obtained by
observing people at work, interviewing users, and studying procedure manuals and other
supporting documentation, questionnaires and visits to other organisations.
• Document the current physical system. A major problem in the past was how to record all
the detail about the system. Most of it could be found only in the analyst's head or draft
notes. Here the basic tools of structured systems analysis such as the data flow diagram
(DFD), the entity relationship diagram (ERD) and data dictionary (DD) can be used to
represent graphically and record the data and procedures. We will discuss these later in the
chapter.
• Define the problem areas. These may include such issues as poor response times in the
existing system, poor presentation of current information, high costs or weak controls in
the current system, waste and sometimes duplication.
• Identify new requirements. The analyst must attempt to identify new user requirements
and look for new and improved procedures that can be incorporated into the system.
• Identify possible solutions. Having derived objectives for the new system from the
previous stage, the analyst now develops a conceptual model of the new system in
conjunction with the user. This may involve the investigation of alternative physical
designs, such as whether to remain with the existing manual system, or to choose a
centralised or decentralised approach to the application.
• The culmination of the analysis stage is the preparation of the formal user requirement
specification (URS) that incorporates a logical model of a system that will meet the user's
requirements. A large proportion of the functional description and data specifications is
best communicated from the analysis stage to the design stage through the graphic and
electronic output from the structured tools used in the analysis process (data flow
diagrams, entity relationship models, decision trees and the data dictionary).
• Again management is required to review the status of the project and to make its go/no-go
decision.
12.1.3 Systems Design
The analysis stage of the SDLC has clearly identified what must be done in order to meet the
user's requirements. One important decision that must be taken at this point is whether to
"make or buy" the new software application. In the past, most large organisations developed
their own applications as no two organisations were exactly alike, and they could afford the
136 Discovering Information Systems
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investment in systems developed around their user's needs.
Today the picture is changing as custom-built software is becoming very expensive to
develop and even more so to maintain. Computer applications are large, complex and
integrated and many businesses have become non-competitive because of their inability to
develop systems that adequately support their business activities.
On the reverse side, packages (pre-written software applications) are becoming more
common and can be customised to meet the needs of each organisation. With major benefits
in terms of speed of installation, cost, low maintenance and low risk, more and more
companies are switching to packaged applications software. It is at this stage in the SDLC that
the "make or buy" decision must be taken. We have analysed our user's requirements and can
use these as selection criteria in searching for an appropriate package to purchase and install.
Where there is no suitable package available we can still look to other innovative ways of
obtaining the software, such as hiring contract staff or appointing a software house to build
the system for us. Purchasing pre-written software will obviously mean the detailed systems
design, coding and testing phases of the project are bypassed, depending on the need for
customisation of the final system. In later courses we will look at the package selection
process in more detail.
The objective of the design stage is to determine exactly how the new system will work, and
to communicate this information in a document referred to as the detailed systems
specification. If we take the analogy of an architect building a house, in the analysis stage he
has determined the feasibility of the project and identified the owner's requirements in terms
of the positioning of the house on the plot, size and architectural style, number of rooms and
so on. The architect may even have built a small model to demonstrate the look and feel of the
new dwelling. Once the owner is happy that the proposed house meets his requirements, the
architect must communicate the detailed design to the builders. This would entail the drawing
of a detailed plan of the house, specifying exactly how every part of the building is
constructed and defining dimensions, materials, construction techniques etc.
We need to go through the same process when designing computer systems. This includes the
design of:
the technical platform on which the software will run. The new application may need
new hardware, operating systems software and network connections
output reports and enquiry screens
input forms and data capture procedures
physical file and database layouts
description of the workings of each program module
new clerical processes and procedures that will be required to interface with the new
system.
Whereas in the analysis stage the emphasis was on identifying the user's needs with little
concern for the way the computer would be used, the design stage also requires user
involvement for the approval of detailed design, but the physical constraints imposed by the
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12. System Development Section IV
computer are also of major importance. Gane and Sarson [1979] define the objectives of
structured design as follows:
"The most important objective of design, of course, is to deliver the functions required by the
user. If the logical model calls for the production of pay cheques and the design does not
produce pay cheques, or does not produce them correctly, then the design is a failure. But
given that many correct designs are possible, there are three main objectives which the
designer has to bear in mind while evolving and evaluating a design:
• Performance. How fast the design will be able to do the user's work given a particular
hardware resource.
• Control. The extent to which the design is secure against human errors, machine
malfunction, or deliberate mischief.
• Changeability. The ease with which the design allows the system to be changed to, for
example, meet the user's needs to have different transaction types processed.
The output from systems design is a detailed design specification incorporating technical,
input, output, data and process specifications. In the past, much of the information was
communicated in written form which was difficult to understand and often ambiguous.
Imagine the builder having to construct a house from a written description. Like the output
from analysis we have a number of innovative tools to help users and developers understand
and communicate the workings of the system. These include data models and data
dictionaries, screen and report layouts, structure charts and pseudo-code. We will look at most
of these later in this chapter.
12.1.4 Systems Build
In this stage we program the new system. If the system has been purchased "off-the shelf,
this phase would consist of the customisation of the system. The success of the
implementation stage is heavily reliant on the previous stages. If the analysis stage was poorly
enacted, the system may not be what the user requires. Poor design will make it difficult for
the programmer to construct the system, and it may be inefficient and difficult to maintain.
However, if the required effort and expertise is invested in analysis and design, there will be a
precise specification of what to build available to the IS programmers and technical staff.
Unlike the previous stages, the programming stage can be undertaken as a number of separate
tasks, performed in parallel. Programmers can code, data base administrators set up the
database, hardware suppliers install and test networks and equipment, and we can begin to
train the end-users to prepare them for the implementation phase. With so much happening,
and with the need for some tasks to be completed before others begin, the analyst must
develop a detailed project implementation plan to ensure tasks are scheduled and delays are
quickly identified and addressed. Programming includes the following steps:
• database construction
• program coding and testing
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Section IV 12. System Development
• systems testing to check the system can handle expected loads and meets physical
performance criteria
• finalise manual procedures
12.1.5 Systems Implementation
This entails the transition of the completed system into the operational environment, and
includes the following tasks (some of which will already have been started in earlier phases):
• installation and testing of any new hardware, systems software and network
infrastructure
• train users and operations staff
• transfer data (data conversion)from the manual or old system to the new database
where necessary
• perform acceptance testing. This requires careful planning to ensure all data flows,
error procedures, interfaces, controls and manual procedures are tested
• complete project documentation
The change over carries some risk, as failure of the new system may result in the organisation
being unable to do business, There are a number of approaches to converting from the old
system to the new. The least risky is to run the new system in parallel with the old until the
new system is stable. There is obviously a cost to running both systems. Another approach is
to convert one part of the organisation at a time (for example one branch office at a time).
This method (known as the pilot method) reduces risk and allows the development team to
focus on one area. This approach can cause some integration problems as part of the
organisation is running on the old system and part on the new. A similar approach is the
phased implementation method where organisations convert to a large system one step at a
time. For example they may start with the stock system, then implement debtors and finally
the order entry system. Some organisations use the big bang approach and just switch over
from the old to the new system. This option is obviously high risk as there is no system to fall
back on in an emergency.
When the new system has been in operation for a few months, a post-implementation audit
should be carried out. This audit must ascertain whether the project has achieved the initial
objectives specified in terms of:
meeting initial scope and objectives
anticipated costs and benefits to the organisation
user satisfaction with the new system
performance (response/turnaround time, reliability)
adherence to standards
quality of final product
project performance in terms of cost and time.
This exercise will help to highlight problems that require maintenance of the new system and
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provide valuable feedback to IS management and project teams to assist in future
development exercises.
12.1.6 Maintenance
Finally resources will be required to maintain and enhance the system over its operational life
which can vary between 4 and 10 years. There is normally a formal hand-over of the system
from the project team to the maintenance team. This will ensure that there is a defined time
when the project is completed and that all the required documentation is produced. There are
many systems in existence that are still supported by the original developer; and all
knowledge of the system exists only in that individual's head. The problem is that when this
person leaves (or worse gets run over by a bus), there is no one with any knowledge of the
system and the organisation is at risk.
Research has shown that this is the most expensive stage of the life cycle as program bugs
(as a result of poor design or bad coding and testing) or enhancements (poor analysis of
user's requirements or changes to the business) require continual analysis and programming
effort.
The following table summarises the important tasks in the six stages of the SDLC and
highlights the main deliverables from each task.
Stage
Tasks
Deliverables
Preliminary
Investigation
Problem Definition
Scope and Objectives
Data Gathering
Risk Assessment
Feasibility Analysis
Project Charter
Feasibility Study
Systems Analysis
Data Gathering
Systems Modelling
User Requirements
Definition
User Requirements
Specification
Systems Design
Make or Buy Decision
Physical Systems Design
Technical Design
Detailed Systems
Specification
Systems Build
Programming and testing
Platform Implementation
Production System
Systems
Implementation
User Training
Data Conversion
Systems Conversion
Post-Implementation Review
Live System
Systems
Maintenance
Fix system "bugs"
System enhancement
Working System
Figure 12-2: SDLC Tasks
12.2 Development of Structured Methodologies
New and innovative systems development techniques are frequently proposed by researchers
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and practitioners and, over time, these formal methods have replaced the traditional pragmatic
approach to developing computer systems.
12.2.1 Structured Programming.
In the 1960's, the major concern in IS development environments was the efficient utilisation
of expensive computer hardware. Programs were written in low level languages with little or
no support documentation and, over time, the code became almost impossible for
maintenance programmers to understand and fix. So arose the need to introduce a set of
standard rules and procedures for writing programs, often referred to as structured
programming. Some of the key techniques in the structured programming approach include:
• a limited set of simple control structures (to control branching and looping)
• standard naming conventions for data and procedures
• self documenting programs.
Structured programming techniques ensured that programs were easier to write and test and
much easier to maintain.
12.2.2 Structured Design.
In the mid 1970s the focus in systems development moved from program coding to systems
design. Computer applications were becoming more complex with the introduction of large
on-line, integrated systems.
IS researchers, and in particular Larry Constantine, studied the problems of program size and
complexity, and determined that, as a problem grew in size, so there was a more than
proportional growth in the complexity of the problem and therefore in programming time. He
advocated that all systems should be made up of small modules each no longer than fifty lines
of program code.
Fragmenting a problem into a number of modules can be done in many ways; and he urged
that the best technique would be to segment the program by function (task) with each module
being as functionally independent of other modules as possible. This would ensure that
changes to one program module were unlikely to affect other modules.
This technique was known as structured design; and a graphical representation of the
modules and their relationships known as a structure chart, was developed to assist in the
process.
12.2.3 Structured Analysis.
In the late 1970s the focus in systems development moved again, this time to the analysis
stage. IS professionals had formalised the design and coding of computer software but had
neglected the most important development issue - what are the user's real requirements.
Written specifications were the main source of communication throughout the project. In the
same way that architects would never attempt to describe a building in a letter, so analysts
needed tools and techniques which could be used to define and communicate the user's
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requirements to the systems design stage. These structured tools and techniques included:
• Data Flow Diagrams (DFD). These diagrams are used to show how data flows between
the various processes in the system. DFD's are an excellent communication tool as they
are simple enough for users to understand and yet detailed enough to form the basis for the
systems design process. A number of DFD techniques has been developed since the
original work was published by Tom De Marco in 1978. However, they all basically
perform the same task. Data flow diagrams are one of the most used and popular IS
charting techniques.
• Entity Relationship Diagrams (ERD). Entity relationship diagrams identify the major
objects about which data is stored and chart their interrelationship. Like most formal
techniques, its major value is that it forces the analyst into a structured and detailed
investigation of all the data used in the system.
• Decision Trees and Pseudo-code. These tools enable the analyst to express process logic
clearly and unambiguously. In the detailed analysis of an information system, the analyst
often has to describe a logical process that the future system will have to perform.
Examples of these could be the way that a personnel system calculates pension benefits for
employees or a sales system calculates sales commissions. Decision trees are
diagrammatic representations of the process logic, showing the conditions that need to be
tested and the resulting activities in a simple tree-like structure. Pseudo-code can be
described as "structured English". It permits the analyst to define process logic using
English language couched in the logical structures inherent in program code. In reality it
eliminates the verbosity and ambiguity from the English narrative.
• Project Dictionary. This tool enables the analyst to capture and catalogue the entire
system specification on computer with the obvious advantages in reporting, cross-
referencing and updating. In a database environment, data is no longer the property of each
individual application but managed centrally as a corporate resource. Vast amounts of
information about this data needs to be maintained, for example field names, types and
lengths, validation rules, data structures and relationships. As systems move from the
development to production environment, this data about data is transferred from the
project dictionary into a production data dictionary to enable the database administrator
(DBA) to build and maintain the corporate database.
As we will discuss later, most of the new computer assisted software engineering (CASE)
tools are now built up round a project dictionary.
12.3 Alternative approaches to developing systems
Over the past 40 years, efforts have been made to improve the quality of new systems and to
reduce the time and effort expended in their development. The following section provides an
overview of some of the significant tools and techniques developed for this purpose.
12.3.1 Prototyping
One technique that has been incorporated successfully into the SDLC is prototyping. As the
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Section IV 12. System Development
name suggests a prototype is a mock-up or model of a system for review purposes.
Looking at the traditional SDLC, one of the major problems is that the user is asked to
provide detailed requirements prior to the system being built. Once a system is implemented
he may find flaws in his original requirements or may see the possibilities of a new and
improved approach.
For applications such as general ledger and payroll, the requirements are normally well
understood (and usually standardised enough to suggest the use of packages) but many other
areas such as personnel are unstructured and would benefit from the prototyping stage.
The two main approaches to the use of prototypes in the SDLC are:
• discovery prototyping where the analyst builds a skeleton of the final product in the
analysis stage of the project in order that the user may better understand the workings of
the final system. This prototype is normally built with a fourth generation language and
while it is likely to include mock-ups of screens and reports, it is seldom a fully working
model. The building and refining of the prototype is an iterative process between analyst
and user and stimulates discussion on the functionality of the final product. Once the
analyst and user are happy that the system's requirements have been identified, detailed
requirement specifications are developed and the prototype is no longer required. In some
instances the prototype may serve as the specification.
• evolutionary prototyping where a working model is built with the intention of later
refining it into the operational system. While this technique would appear to have great
advantages in terms of productivity, the original prototype is often thrown together and not
properly designed.
Prototyping can offer IS developers many advantages in that it assists in clarifying user's
requirements, improves user communication and commitment, should improve the
functionality and quality of the user interface and will assist in identifying problems earlier in
the development life cycle.
Where prototyping can be problematic is that it raises the user's expectations that systems are
quick to build and changes are easy. In addition there is a lack of experienced prototypers and
quality prototyping tools.
12.3.2 Joint Application Development (JAD)
One major problem in systems development projects is the lack of real communication,
understanding and consensus between users, management and the development team. Instead
of the traditional one on one interviews spread over weeks and often months, the JAD
approach involves a series of highly structured workshops where stakeholders focus on any
one of the planning, analysis, design and implementation stages of the life cycle. One obvious
advantage of this approach is a reduction in the time it takes to develop systems. However the
real benefits of JAD come from better user requirements through improved communication
and conflict resolution. Successful JAD sessions often depend on the competence of the
session leader (termed the facilitator), the scribe (who is responsible for documenting the
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output from the sessions), strong top management support and a mix of participants with
expertise and responsibility for the area under discussion.
12.3.3 Computer Assisted Software Engineering (CASE)
There is a famous saying, "The cobblers children have no shoes." and this is very relevant to
IS. Here we have a classic example of a group of IS professionals, dedicated to computerising
the organisation in which they work, while developing these computer systems via manual
means.
CASE environments attempt to address this problem by offering a set of integrated electronic
tools for use in the SDLC. During the first phase of system development, CASE products
provide the analyst with computerised tools to complete and document the analysis and
detailed design stages of the development project by graphically modelling the data
requirements and the business process flows that the intended application has to address.
These models attempt to give a visual representation of a part of the business operations,
following one of many modelling standards. The resultant application model is then used as a
blueprint for the actual implementation in computer code. The tools that are geared
specifically for this modelling phase are referred to as upper-CASE or JJ-CASE tools.
Lower-CASE tools specialise in the second phase of system development: the actual
generation of executable applications or advanced prototypes. This is typically achieved
through the use of a generic application generator, although CASE tools tend to be
independent of any specific database management system.
Integrated or I-CASE aims to automate both phases i.e. a combination of upper and lower-
CASE tools in one single package.
Most CASE environments use an electronic project dictionary as a repository and can include:
graphic tools for charting diagrams such as DFD's, ERD's and Structure charts
4th generation languages or application generators to assist with prototyping
data dictionary facilities to record and maintain data about data, processes and other
system details
quality control facilities to check specifications and code for correctness
code generators to reduce programming effort
spreadsheet models to assist with cost/benefit analysis
project management tools to plan, monitor and control the development cycle.
When CASE environments were originally developed in the mid 1980s, IS managers viewed
them as a possible "silver bullet" to resolve the growing demand for computer systems. The
promise of CASE was better quality systems, reduced development time, enforced standards
and improved documentation.
As yet CASE tools have failed to make a major impact. CASE environments are complex, the
cost of implementing CASE is high (both in terms of the CASE software and analyst training)
and many organisations are looking to other solutions (packages and object orientation) to
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Section IV 12. System Development
resolve their applications backlog.
12.3.4 Object Oriented Development (OOD)
Using the traditional development approach where the analyst designs procedures focused on
the user's requirements can result in systems that are costly to develop and inflexible in
nature. The object oriented approach attempts to build components (objects) that model the
behaviour of persons, places, things or concepts that exist in the real world and then to build
systems from these components. We do not design and build unique systems for motor cars or
televisions; they are mostly built up from a set of common, interchangeable components.
Even when components are unique they are very similar to other components. In the same
way we can construct computer systems from building blocks reusing objects from other
systems, making modifications to similar objects or obtaining objects from commercial
component libraries.
The OOD paradigm is only now gaining momentum in the market place and most
programming languages and methodologies do not support 00 development. One exception
is Small Talk, the language credited with pioneering the OOP (object oriented programming)
concept. Today many of the popular programming languages are appearing with 00 versions
(for example Pascal, C++, Visual Basic and even COBOL).
12.3.5 Other development tools
The above-mentioned new programming approaches were not the only attempts to improve
developer productivity. The following presents some other development tools and approaches.
Note that, since distinctions between the categories cannot always be perfect, some tools
could be classified in more than one category.
(5 Visual programming tools. The power of graphical user interfaces and object-orientation
has spawned a number of high-level front-ends or shells to enable non-programmers to
generate their own straightforward applications. These visual programming tools allow
for the construction of applications by selecting, connecting, copying and arranging
programming objects. For simple applications, there is no need for any code to be written
at all since all required objects can be copied from a large library with all commonly used,
pre-configured objects and their associated standard methods.
(5 Report generators are generally associated with database management systems and allow
users to create ad-hoc, customised reports using the data in the database by specifying the
various selection criteria and the desired report layout.
G Application generators consist of standard building blocks that can be combined or
customised to create the required systems. The user specifies the inputs, the output
requirements and the various data validations and transformations. Screen and report
painters allow on-line, visual layout of input and output modules. Generally, these
generators are supported by a comprehensive database management system that integrates
the data dictionary, graphics and reporting modules as well as other utilities such as data
and process modelling, security facilities, decision support modules and query-by-
example (QBE) languages.
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(5 Logic programming for knowledge based systems. Programmers quickly discovered that
conventional programming languages were inadequate to develop advanced knowledge-
based applications, such as expert systems and other artificial intelligence systems. These
systems require reasoning capabilities and have knowledge representation requirements
that are difficult to implement using procedural languages. This led to the development of
logic programming languages such as LISP and Prolog. The use of these languages is
generally confined to researchers and scientists. Today, a number of shells has been
developed that allow the automatic generation of straight-forward knowledge-based
systems.
(S End-user applications. Today's end-user productivity applications have extensive
programming capabilities and allow for customisation by means of macros (pre-recorded
sequences of commands, keystrokes) and formulae. A spreadsheet is essentially a model
developed by an end-user whereby the equations (or data transformations) have been
programmed by means of formulae. Many of these formulae look similar to the
statements in programming languages. The following statement would calculate
someone's weekly wages taking into account an overtime rate of 50%, using Microsoft
Excel or Access.
- IF ( hours > 42 , hours * wage , 42 * wage + ( 1.5 * wage ) * ( hours - 42 ) )
72.4 Critical success factors
Regardless of the development approach that may be used, a number of factors have been
identified that are critical to ensuring the success of a systems development project:
well defined system objectives
careful test of feasibility
top management support
user involvement to ensure strong commitment
rigorous analysis to ensure detailed, unambiguous user requirements
sound detailed design to ensure an efficient, quality, maintainable system
project management to ensure the development team is managed and controlled.
12.5 South African Perspective
Research by a group of Scandinavian computer scientists has suggested that prototyping is
better suited than the traditional SDLC to systems development projects undertaken in
developing countries. Although the SDLC provides a rigorous development methodology
intended to generate clearly defined system requirements, it does not take into account
problems resulting from social and cultural factors. These include the uncertain availability of
technical skills, user anxiety about technology, and the need for adaptability of the final
product to differing local conditions. A further dimension to this approach is the need to train
users in basic computer literacy skills and to inform them about the business role of IS before
any attempt is made to elicit system requirements. Once workers have been empowered in
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this way, they are able to provide more valuable participation in the development of a system.
Developers must also see the project as a mutual learning experience, since they need to
understand how future changes in the business environment may affect system requirements.
12.6 Beyond the Basics
Web pages can contain multimedia effects and interactive capabilities, and the development
of web pages involves using a variety of special components. Among the jargon and
acronyms that you may encounter are the following:
• Hypertext Markup Language (HTML) is not actually a programming language, but has
specific rules for defining the formatting of text, graphics, video and audio on a web
page. Tags are used to indicate how a page should be displayed on your screen, and
the details underlying links to other web pages.
• Interactive elements such as scrolling messages, pop-up windows and animated
graphics are controlled by small programs, generally scripts, applets or ActiveX
controls. Basically, a script is an interpreted program that runs on the client computer,
as opposed to an applet, which is a compiled program running on the client computer.
ActiveX controls are object-oriented technologies that allow components on a
network to communicate with one another.
• Information is sent and received between your computer and a web server via the
common gateway interface (CGI), which is the communications standard that defines
how a web server communicates with outside sources such as a database. CGI
programs are frequently written using scripting languages such as JavaScript, which is
simpler to use than the full Java language.
• Web pages created using dynamic HTML can automatically update their content on
the client's machine, without having to access the web server, making them more
responsive to user interaction. Extensible HTML (XHTML) uses XML technology to
display web pages on different types of display devices, while wireless markup
language (WML) supports browsing on PDAs and cellular telephones. Finally
wireless application protocol (WAP) specifies how wireless devices such as cellular
telephones communicate with the Web.
12.7 Exercises
12.7.1 Stages of the SDLC
Read the following article, and then briefly explain, for each stage of the SDLC, which of the
standard activities appear to have been omitted or not completed when developing the system,
and what effect this had on the quality of the final product.
From: Machlis, S. "U.S. Agency Puts $71m System on Ice", Computerworld, 12 May
1997.
The U.S Agency for International Development (AID) last week confirmed that it
suspended overseas use of a new computer system plagued by integration snafus,
data transmission bottlenecks, and response times so slow that employee efficiency
suffered. For now, 39 field sites will go back to using the agency's old system for core
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accounting services and procurement contracts while problems with the Washington-
based computers are ironed out. "We need to get the core functionality established",
said Richard McCall, AID's chief of staff.
The New Management System (NMS), budgeted at $71 million, has been under fire
since it was deployed in October of 1997. The AID inspector general's office criticized
NMS for data errors and slow performance. In some cases, users had to spend days
trying to process a single transaction.
The new system can't handle the large amount of data that passes among AID
offices, McCall said. The agency must decide whether to boost expensive satellite
network bandwidth to handle real time transactions or move to some batch
processing. "I don't think people understood the amount of data that would be
transmitted over the system", he said.
Designers also initially failed to gasp the difficulty of integrating legacy accounting
systems. "We thought we had three primary accounting systems," McCall said. But
numerous infield alterations to basic systems over the years meant the agency had
closer to 80 different accounting systems. Some of the resulting data didn't import
correctly into the new system.
In addition, McCall said, system designers should have stayed focused on core
requirements instead of trying to immediately add features that users requested after
early tests. For example, some overseas employees wanted to be able to call up
data from any foreign site. Although that is an attractive feature, he said, "that taxes
the system. You don't really need that now."
12.7.2 Systems conversion
Four different methods have been described for the conversion to a new system: the parallel,
pilot, phased or "big bang" approach. Compare these four alternatives in terms of the likely
time frame involved, level of risk incurred, and user "buy-in" to the new system.
148 Discovering Information Systems
Section IV 13. Using Information Systems
13. Using Information Systems
Many factors can affect the ability of an information system to fulfil its goal of supporting
business processes. Before an information system is developed, its purpose must be aligned
with the goals of the business, a cost benefit study should be completed, and user
requirements must be carefully analysed to ensure that it will provide the appropriate
functionality. During the system development process, organisational standards need to be
adhered to in respect of the various deliverables of the SDLC and the overall IT architecture
of the organisation. But over and above these planning and acquisition issues, the final
measure of success for an information system depends on how it is used - are employees
happy to incorporate it into their data processing activities; does it deliver the information that
they need; is the integrity of information guaranteed; can human or technical problems be
identified and corrected? No matter how carefully a system has been developed, there are still
potential problems associated with its use in the real world, which need to be included in an
IS management strategy.
13.1 Change Management
One of the main reasons that information systems fail, is that users resist change. Many
individuals believe that their skills and experience will be of less value in an automated
environment, which threatens their job or status. Users may refuse to adapt to new methods of
working, or while using the new system may attempt to undermine its efficiency. Acceptance
of the system can be significantly improved through the implementation of a change
management strategy.
During the systems analysis phase, users should be involved in the identification of problems
that occur in existing systems, and given the opportunity to express their own information
requirements. If they are made aware of shortcomings in the old system and of how these will
be alleviated when the new system has been implemented, then they are more likely to accept
the change. Where decisions need to be made between alternatives, users should be part of the
decision-making process rather than being presented with a unilateral solution.
The design phase of the SDLC involves the "make or buy" decision. The evaluation of
commercial packages should be done by a team that includes users as well as managers and
technicians, so that any operational concerns can be raised and clarified. If a system is to be
developed in- house (or outsourced), then the users should be consulted about the layout of
screens for data capture, and the format of reports. Finally, if the new system will result in
changes to existing work procedures, the impact should be discussed and any problems or
training needs identified.
User training falls within the systems implementation stage of the SDLC, and should involve
more than just teaching users how to operate the new system. They must also understand what
the purpose of the system is, what benefits it is expected to generate for the business, what
problems could result if it is incorrectly used, and the importance of their role in its successful
implementation.
Discovering Information Systems 149
13. Using Information Systems Section IV
13.2 Ergonomics
Ergonomics refers to design principles that support safety and efficiency in the workplace.
Uncomfortably aligned computer monitors and keyboards, or the incorrect height of chairs
and desks, may result in neck or back pain; eye strain can be caused by screen glare or poor
display resolution; and repetitive strain injuries (RSI) such as carpal tunnel syndrome, may
affect the wrists and hands of data entry personnel. Correct attention to ergonomics will not
only reduce health risks, but also improves employee morale and productivity.
Examples of how ergonomic principles can be incorporated in an IS environment include:
• The use of keyboards with built in wrist rests
or specially contoured design to reduce RSI.
• Chairs with variable seat height and back
support.
• Correct adjustment of the angle of computer
monitors.
• In addition to adjusting the brightness and
contrast of the computer monitor, an additional transparent screen can be used to
reduce glare.
An infrequent but potentially life-threatening new health hazard that has recently been
identified by medical practitioners is "e-thrombosis", which may result from sitting immobile
for long periods. This is similar to the condition sometimes experienced by travellers on long
flights, in which a blood clot forms in the leg veins, and may subsequently break off and
travel to the lungs or other vital organs.
13.3 Ethics
The increased use of information systems in business has given rise to new opportunities for
behaviour that could negatively affect the organisation, its employees and its customers. The
study of ethics examines the moral quality of a decision or course of action, and is based on
what is right rather than what is legal. Four major areas of ethics that are affected by
information technology are privacy, property, accuracy and access, and many businesses have
a code of ethics determining the expected standard of conduct for their employees.
13.3.1 Privacy
Most companies store information about their customers and staff in corporate databases - not
only details like names and addresses, but also transaction histories, payment records, etc.
One ethical issue regards the privacy of that information. By law it may not be passed on to a
third party without the consent of the subject of the information. However, within the
organisation itself accumulated information may be used, for example through data mining or
neural networks, to decide on credit limits or to target customers for promotions, even though
the information was not originally supplied with that use in mind. A member of staff who
applies for a more senior post, may find that her previous record of sick leave influences the
outcome of her application. If you were ill on the day of your final IS exam, you would apply
1 50 Discovering Information Systems
Section IV 13. Using Information Systems
to write a deferred examination: would you think it fair to have your performance in other
courses taken into account when deciding whether the deferred exam for IS should be
granted? Another cause for concern is the viewing of personal data by employees when this is
not actually required for business purposes: if an attractive member of the opposite sex joins
your organisation, is it ethical for you to check his/her age and marital status? What about
HIV status? And in many countries, governments are now debating the balance between the
right to personal privacy of information and the need for national security.
13.3.2 Property
Computer software and data have been the subject of a number of ethical issues related to
property. Software piracy (the copying of copyrighted software) is illegal, but what about the
copying of software that has not been copyrighted? If you are confident that you can get away
with copying your friend's tutorial preparation, do you think that it is acceptable to do so?
Copying of other people's ideas without acknowledgement is plagiarism, which is generally
regarded as unethical even if society does not always consider it to be illegal. Employees who
leave an organisation may take with them confidential knowledge about the firm and its
business plans, which they gained while they were working for the organisation but which
could be useful to a competitor. Even within the organisation itself, employees may be
reluctant to volunteer their knowledge for inclusion in an expert system, since this may reduce
their own importance. The Internet has facilitated the unauthorised copying of intellectual
property across national boundaries, such as the swapping of music files between individuals,
which is practically impossible to control without the cooperation of the individuals involved.
13.3.3 Accuracy
Accuracy of information at the transactional level can to some extent be controlled through
validation checks within the database and software design. Individuals are entitled by law to
check and correct personal information that is stored in corporate databases. Nevertheless,
since the users of information systems are human and fallible, the use of technology alone
will not prevent the production of inaccurate information, either intentionally or by accident.
Again, the growth of the Internet has made the dissemination of incorrect information
extremely difficult to control, and raises ethical issues about the responsibility for its
consequences. An unresolved problem concerns the retouching, or digital alteration of
photographs, where the key issue appears to be whether the intended information content of
the image has been changed.
13.3.4 Access
Access to information can be protected through the use of technology, such as passwords,
electronic and biometric controls. Databases can allow or restrict access for different types of
users. But what about equal access to information for those who do not have computers, or
who are unable to use them because of physical disabilities? Many people feel that it is
unethical for society to condone the lack of access to information for specific groups. On the
other hand, employees who have access to organisational computing resources are often
guilty of abusing the privilege by using company time and equipment for personal pursuits
such as emailing and web surfing.
Discovering Information Systems 151
13. Using Information Systems Section IV
13.4 Data Processing Controls
An important function in computer auditing is the review and analysis of information systems
security. One element of this is physical access control; another is software-based data
processing controls that are intended to prevent data errors from occurring, to identify any
errors that have occurred, and to assist with recovery from errors. Validation checks may be
built into the database structure, or coded as part of a software application, to enforce business
rules such as credit limits or minimum and maximum charges. Network and database access
may be selectively restricted, and network monitoring software keeps track of which users log
on to the system, what files they access, and what changes they make. Audit trails provide a
transaction history showing where each entry originated and who was responsible, and serve
an important function not only in identifying the source of problems but also in determining
where staff training is needed. Sequential numbering of transactions and of audit reports
ensures that every business activity is recorded. Where financial totals are transferred from
subsidiary journals to the general ledger, the corresponding general ledger audit report should
cross reference the audit report that reflects the individual transactions, and control totals in
both ledgers must be reconciled. Exception reports should be produced in the case of
transactions or totals exceeding previously specified limits.
Further data processing security for complex transactions can provided by database
management systems. A single transaction may result in updates to a number of different
files, e.g. a sale will affect both the accounts receivable and inventory files. In this case, all
the required updates must be made successfully before the transaction is committed to the
database; if an error occurs at any stage after the start of processing, then all the updates will
be rolled back (i.e. undone), to prevent the possibility of inconsistent entries.
Additional management controls should be implemented to reduce data processing risk.
Employees should be thoroughly trained in the software and procedures that they are expected
to use. Regular backups should be made and stored in secure off-site locations. Separation of
duties among employees reduces the risk of deliberate fraud, and awareness of ethical
standards should be a part of company policy.
13.5 Disaster Recovery
Natural disasters, sabotage, theft, viruses - any of these can result in damage to, or even
destruction of, an organisation's information systems. Reliance on corporate databases and
powerful servers increases the vulnerability of the system. A disaster recovery plan is needed
to document how the business would be able to recover from either the total loss of
computing capabilities, or else the interruption of critical services.
Regular backup of data and programs is the first essential for recovery from mishap. Backups
should be kept off-site and in a fireproof container or safe, and should be tested at intervals to
ensure that the restore procedures function successfully.
A hot site provides an alternative computing facility that can be used in the event of a major
disaster, such as occurred at the World Trade Centre in New York in September 2001.
Backup copies of application programs and corporate data can be run on equipment at the hot
site with minimal interruption to business. Because the duplication of computer hardware is
152 Discovering Information Systems
Section IV 13. Using Information Systems
expensive, this facility may be shared between a number of firms operating in different
geographical locations. (In fact, the internal systems used to manage the twin towers of the
World Trade Centre, each had their disaster recovery facilities located in the opposite tower,
since the likelihood of both towers being destroyed simultaneously was believed to be
remote.)
Some disasters can be minimised through avoidance and early warning systems. An
uninterrupted power supply (UPS) will prevent data corruption resulting from power spikes,
and in the event of a total power failure, can run the system for a limited period before
shutting it down in an orderly fashion and without data loss. Temperature control systems,
smoke detectors and water sprinklers or gas fire suppression systems should be installed to
reduce fire risk, while physical controls such as door locks and alarm systems will protect
against unauthorised intruders. Expert systems can be used to monitor the network for faults
and to protect against communications threats such as viruses and hackers.
13.6 How IS Affects You
Every department of an organisation uses information technology in some way, and even if
you are not an IS major, IS is likely to be an important element of your future career in
commerce.
•
In finance and accounting, information systems are used to forecast revenues, plan
business activities, manage financial resources and audit the performance of the
organisation.
• In sales and marketing, information systems are used to determine the potential
market for new products, to plan advertising campaigns and predict sales revenues, to
determine product prices and manage customer relations.
• Many of the processes in an organisation's value chain can be enhanced through the
use of computer-based information systems, from procurement to manufacturing to
after-sales service. The operations manager who has a sound knowledge of
information technology will be able to apply it effectively in order to maintain
competitive advantage in the market.
• Human resource management is no longer focused solely on employee record
keeping. The internet has become a powerful employment tool; company intranets
empower staff to manage their benefits, leave and training requirements. IT now has
an important role to play in the hiring and retention of staff.
• Of course, if you intend becoming an IS specialist, then the development and
management of information systems will be central to your future career, and this is
only the beginning of your studies in the field of IS. Even if you focus on a particular
aspect of IS, such as database or network administration, you will need a solid
foundation of basic principles that will enable you to integrate your area of
responsibility with the goals of the business and the IT architecture that supports
them.
Whatever your future career, we trust that your introduction to information systems will have
opened your eyes to the wide variety of ways in which IS can be used to support the activities
Discovering Information Systems 153
13. Using Information Systems Section IV
of any business.
13.7 South African Perspective
The Computer Society of South Africa (CSSA) has adopted the following code of conduct for
its members:
"A professional member of the Computer Society of South Africa:
1 . Will behave at all times with integrity. He or she will not knowingly lay claim to a
level of competence that he or she does not possess and he or she will at all times
exercise competence at least to the level he or she claims.
2. Will act with complete discretion when entrusted with confidential information.
3. Will act with impartiality when purporting to give independent advice and must
disclose any relevant interest.
4. Will accept full responsibility for any work which he or she undertakes and will
construct and deliver what he or she purports to deliver.
5. Will not seek personal advantage to the detriment of the Society.
6. Will not discriminate on the basis of race, sex, creed or colour."
13.8 Beyond the Basics
When an organisation invests in new technology, four different stages are experienced in its
assimilation. If these are understood and supported by management, the introduction and
spread of the technology can be facilitated.
Phase 1: Technology identification and investment. A team of technological specialists and
business users is needed to explore and evaluate new technologies. When the decision is
made to acquire a new technology, the initial investment should include staff training and
management of the implementation.
Phase 2: Technological learning. Staff must be supported in their efforts to use the new
technology, and encouraged to experiment in order to gain experience and knowledge of its
capabilities. Use of the system should not be restricted only to existing business tasks.
Phase 3. Technological learning. Technical staff and experienced users together define
possible applications of the new technology and determine the most cost-effective ways in
which it can be incorporated within business processes.
Phase 4. Widespread technology transfer. Once the new technology has a base of
experienced users and clear plans have been developed for its future use, it can be transferred
throughout the organisation. At this stage, tighter management control instead of the previous
policy of experimentation is needed to achieve the expected return on investment.
154 Discovering Information Systems
Section IV 13. Using Information Systems
13.9 Exercises
13.9.1 Ethics
Would you consider the following scenarios to be ethical or unethical? Explain why you think
this.
• A company requires employees to wear name badges that track their whereabouts
while they at work.
• The network manager reads an employees e-mail.
• An employee forwards an e-mail to a third party without obtaining permission from
the sender of the message.
• An employee uses his computer at work to send personal e-mail to a friend.
• A student uses the university computer labs to send personal e-mail to a friend.
• A student copies text from the Web and incorporates it in an essay without
acknowledging the source.
• A student is required to create a Web page for an assignment, so she finds an existing
page that she likes and then modifies its contents.
Discovering Information Systems 155
Case Study Section IV
CASE STUDY: CREAM ADVERTISING
Refer back to the Cream Advertising case study that was introduced at the end of Chapter 10.
Jade Smith has come to the conclusion that rather than trying to add new functions to her
existing information systems, which are in any case somewhat outdated, new systems should
be introduced at all levels of the organisation. This would include applications to provide
transaction processing support, management reports, trend analysis and forecasting, and
access to information about their market and competitors. Groupware would be an important
factor in supporting team work and client communications.
Jade is also is concerned about the growing number of rival advertising companies who have
included the internet in their business strategies. She is reluctant to spend money on
something that will not necessarily increase business income, but she is aware that her clients
feel that Cream is falling behind the times. In her view, the only way that the added expense
of e-commerce would be justified, is if they are able to expand their business to cater for a
global market and attract new overseas clients.
(a) Explain why it is important to plan for the integration of the different systems, rather than
simply acquiring individual software packages and the appropriate hardware from
different vendors?
(b) It will probably be necessary to develop software interfaces between the various systems
to ensure that data can be transferred between them. Would you advise Jade to employ a
technical programmer for this purpose, or should the job be outsourced?
(c) How can Jade best manage the introduction of the new systems to ensure that staff will
use them as efficiently as possible? What ongoing support arrangements should be put in
place?
(d) The new systems will give all staff access to the internet, as well as to corporate data and
applications. What ethical problems might arise and how can they be pre-empted?
(e) In expanding to a web-based global marketplace, are there any cultural or social issues
that Jade should be alerted to?
156 Discovering Information Systems
Index
INDEX
3GL62
80/20 principle 31
acceptance testing 144
Access 156
Accuracy 156
ActiveX controls 152
ad hoc reports 4
AI104
ALGOL 62
alias 88
ALU 41
Analysis 140
application generator 60
Application generator 151
architecture 89 131
Arithmetic and Logic Unit 41
Artificial Intelligence 8
ASCII 12
assembler language 62
assimilation 159
attribute 64 87
B2B e-Commerce 110
B2C e-Commerce 109
Back-door 117
backup 157
bandwidth 71 74
banner 109
Barcode scanners 39
BASIC 63
batch mode 98
big bang approach 144
binary 11
Biometric devices 40
Biometrics 124
bi-stable 11
bit 11
black box 26
boot program 45
boundary 24
bridge 72
browser 77
BTW76
bug 145
bus network 70
business analyst 136
Business applications 58
business process reengineering (BPR)
8
byte 15
C++ 64
Cache memory 45
CASE 149
CD-R 48
CD-ROM 48
centralised processing 89
Chain printer 5 1
Change Management 154
chief information officer 136
Classification of Information Systems
2
client 90
client- server 90
client-server model 90
coax 71
Coaxial cable 71
Codd 85
Collaborative commerce 111
command-based interface 55
common gateway interface 152
Communications Management 67
compact disk recordable 48
Compiler 60
component 25
compound documents 6
Computer Assisted Software
Engineering 149
computer network 69
Computer Science ii
computerised information system 35
conceptual schem 88
continuous system 28
Control 26
Control Unit 41
controller 27
Controls 157
convergence 95
cost centre 133
Cost-benefit analysis 132
country code 75
CPU 41
CRT 49
cybernetics 27
data 36
Discovering Information Systems
157
Index
Data 10
data conversion 144
data dictionary 88
data encyclopaedia 88
data flow diagram 141
Data Flow Diagram 147
data glove 39
Data management software 6
data mart 105
Data mining 106
data visualisation 106
Data warehouse 105
database 81
Database Administrator 88
database approach 81
database management system 82
Datel 72 73
DBA 88
DBMS 82
decision making process 97
decision support systems 95
Decision Support Systems 59 100
Decision Tree 147
design phase 154
design specification 143
desktop 57
device drivers 67
DFD 141 147
dial-up 72
dichotomy of information work 97
differentiation strategy 103
Diginet 73
Digital camera 40
digital cash 112
digital certificates 113
Digital Video Data 48
digitisation 13
Digitiser tablet 39
direct access 47
Disaster Recovery 157
discovery prototyping 148
Discrete systems 28
disk drive 46
disk farm 46
diskette 47
distributed computing 89
Distributed processing 89
documentation 144
domain 75
Dot-matrix printer 50
drum 5 1
DSS 4 59 100
DVD 48
Dvorak keyboard 38
dynamic system 28
EBCDIC 12
EDI 59
EDP95
EEPROM 46
effectiveness 98
efficiency 98
EFT 59
Electrically Erasable Programmable
Read- Only Memory 46
electronic calendar 6
Electronic data interchange 111
electronic data processing 95
Electronic funds transfer 111
electronic mail 75
Electronic mail 7
Electronic malls 109
Electronic payment systems 111
e-mail 7 75
e-mail address 75
emergent property 29
emoticon 76
encapsulate 64
Encryption 113 119
end user computing 95
End-user 136
End-user application 151
end-user computing 134
enterprise resource planning 59
Enterprise-wide system 59
entity relationship diagram 141
Entity Relationship Diagram 147
entropy 30
environment 24
EPROM 45
erasable optical disk 48
erasable optical disks 48
Erasable Programmable Read-Only
Memory 45
ERD 141 147
Ergonomics 155
ERP59
Ethics 155
event-driven 64
evolutionary prototyping 148
exception report 3
exception reports 100
executable 60
158
Discovering Information Systems
Index
Executive Information System 4
Executive Information Systems 102
Executive Information/Support
Systems 59
Expert system 104
expertise 19
extranet 111
fat client 90
fault-tolerant 47
feasibility study 140
feedback 27
FEP71
fibre-optic 71
field 84
file 83
file server 69
file transfer protocol 78
Finger imaging 125
firewall 118
First generation language 61
fixed length field 84
Flaming 76
Flash RAM 45
floppy diskette 47
foreign key. 86
FORTRAN 62
Fourth generation language 63
fraud 116
free-form database 88
Front-end processor 71
ftp 78
game interfaces 39
Gantt chart 135
GB 16
General purpose software 58
geographical information system 58
gigabyte 16
GIS58
goal seeking 102
granularity 26
graphical user interface 57
Groupware 6
GUI 57
Hackers 118
handheld computer 57
hard drive 46
hardcopy 50
hardware 35
hex 61
hexadecimal 61
hierarchical data model 85
holism 29
holographic disk storage 48
Horizontal applications 59
host 74
host-centric processing 89
hot site 157
HTML 78 152
http 78
hypertext 77
I-CASE 149
Illogical Process 121
impact pinter 50
Infobahn 74
Information 16
Information Highway 74
information intensity 103
Information Science iii
information system 25 35
inheritance 87
in-house development 133
Inkjet printer 5 1
input 24
Input devices 37
installation 144
integrated CASE 149
Integrated Services Digital Network 74
interface 25
Internal audit 136
Internet 74
Internet Service Provider 77
Inter-organisational system 59
Interpreter 61
Intranet 111
IOS59
Iris scanning 125
IS architecture 132
IS Frameworks 130
ISDN 74
ISP 77
JAD 149
JAVA 64
JIT 103
Joint Application Development 149
joy stick 39
just-in-time 103
KB 15
keyboard 38
kilobyte 15
Knowledge 19
Knowledge management 20
knowledge workers 123
Discovering Information Systems
159
Index
knowledge-based system 104
kpbs 73
LAN 69
Laser printer 50
LCD 49
legacy system 81
life cycle 139
Lightpen 38
line printer 5 1
liquid crystal display 49
LISP 151
Local Area Network 69
Logic programming 151
logical data view 88
LOGO 63
Low-cost strategy 103
lower-CASE 149
machine language 60 61
macro 151
macro virus 119
magnetic card reader 40
Magnetic ink character recognition 40
magnetic tape 47
magneto-optical drive 48
main memory 44
Mainframe computers 37
Maintenance 145
make or buy 142
MAN 69
Management information system 3
management information systems 95
Management Information Systems 59
100
manual information systems 35
many-to-many 85
MB 15
Measuring Data 15
Measuring Information 18
megabyte 15
megaflops 43
Memory management 66
menu-driven user interface 56
message 64
method 64
Metropolitan Area Network 69
MICR 40
microprocessor 42
Microsoft Windows 57
middleware 106
MIDI 52
MIPS 42
MIS 3 59 100
mobile commerce 109
Mobile devices 37
modem 72
modulation 72
monitor 49
Monitoring 122
Moore's Law 43
Moore's law 45
motherboard 45
mouse 38
MS-DOS 65
Multiplexers 71
Multitasking 66
Multi-user 66
Musical Instrument Digital Interface
52
MVS55
nanosecond 42
Natural language 104
natural language processing 58
negligence 121
Net 74
Netiquette 76
Netizen 76
Network cable 71
Network card 7 1
network data model 85
network diagram 135
network topology 70
newbie 77
newsgroup 78
niche marketing strategy 103
NLP 58
Normalisation 86
Novell Netware 56
OAS5
object 87
object code 60
object-orientation 87
Object-oriented language 64
OCR 39
Office Automation System 5
OLAP 105
one-to-many 85
online 77
On-line analytical processing 105
On-line auctions 109
on-line update 99
OO 64 87
OOD 150
160
Discovering Information Systems
Index
OODBMS 87
OOP 150
op codes 60
open system 27
operating system 65
Operating Systems 65
operation codes 60
operational management 3
Optical character recognition 39
optical computing 44
Optical disk 47
Optical fibre 71
Optical mark readers 40
optical scanner 39
Optical storage 47
organic computing 44
Organic light-emitting diodes 49
OS 65
output 24
Output Devices 49
Outsourcing 134
pack 46
package 142
packet 73
Packet Assembler & Disassembler 73
PAD 73
PAN 69
parallel implementation 144
parallel processing 43
parent-child relationship 85
PASCAL 62
PDA 57
Pen-based Interface 57
Peripheral handler 67
Personal Area Network 69
Personal computers 37
personal digital assistants 57
pervasive computing 95
phased implementation 144
picosecond 42
pilot 144
pixel 14
Plotter 51
Pointing devices 38
portal 109
portfolio 131
post-implementation audit 144
Power-user 56
preliminary investigation 139
Presentation graphics 6
primary memory 44
printer 50
privacy 155
Privacy 122
procedural language 62
procedures 35
Process control 52
productivity software 58
program 55
Programmable Read-Only Memory 45
Programmer 136
programming 143
programming language 60
project charter 140
Project Management 134
Project management software 7
project manager 136
Prolog 151
PROM 45
property 156
protocol 78
Prototyping 148
PSDN 73
Pseudo-code 147
PSTN 72
Public Switched Data Network 73
Public Switched Telephone Network
72
purpose of a system 26
QBE 151
Qualities of Information 17
quantum states 44
query language 63
query-by-example 151
RAID 46
RAM 44
Random Access Memory 44
raster 14
Read-Only Memory 45
realtime 99
record 83
reductionism 29
Redundancy 3 1
redundant arrays of independent disks
46
relational data model 85
relationship 86
removable disk drive 46
repetitive strain injuries 155
Report generator 151
Representing Data 1 1
requisite hierarchy 31
Discovering Information Systems
161
Index
requisite variety 30
Retinal scanning 125
ring network 70
Robotics 104
ROM 45
root 85
Router 72
SAANA 40
Sabotage 117
salami technique 116
sample 13
Saponet 73
Saponet-P 73
scenario 102
scheduling 66
Scientific applications 58
SDLC 139
search engine 77
Second generation language 62
Secondary storage 46
Secondary storage management 66
Secure Sockets Layer 113
sensitivity analysis 102
sequential access 47
Servers 37
Shouting 76
silver bullet 150
SIMMS 45
Skimming 116
Smalltalk 64
smiley 76
snail-mail 75
software 55
Software 35
Software Acquisition 133
software packages 134
software piracy 120
Sound synthesiser 52
source code 60
Spam 124
specification 143
Speech synthesis 52
spreadsheet 151
Spreadsheet 5
stand-alone computers 36
star network 70
state 64
static system 28
stiffy diskette 47
storage medium 1 1
strategic importance grid 131
strategic information systems 103
strategic management 4
structure of a system 28
Structured Analysis 147
Structured Design 146
Structured Programming 146
Sub-optimisation 31
subschema 89
sub- system 25
Supercomputers 37
supply chain 110
supra-system 29
surfing 77
system hierarchy 29
system methodology 130
system state 28
system utilities 67
System Utilities 67
Systems 23
systems analysis 154
Systems Analysis 140
systems analyst 136
Systems Concepts 27
Systems design 141
systems development life cycle 139
systems implementation 154
Systems Implementation 144
Systems View 24
table 83
tactical management 100
Tactical management 3
TCP/IP 78
telecommunications 69
telecoms 69
Telkom 72
Telkom400 73
telnet 78
terabyte 16
teraflops 43
Terminal Spoof 117
the key field 84
Thermal printer 5 1
thin client 90
Third-generation language 62
three tier model 91
token ring 70
touch pad 39
touch pen 38
Touch-screen 38
Touch-tone device 40
TPS 2 59
162
Discovering Information Systems
Index
trackball 38
train 144
training 144
transaction processing system 2
Transaction Processing Systems 59 99
transformation 24
Trojan horse 117
Twisted pair 71
two-tier model 91
Type I decisions 97
Type II decisions 97
unemployment 124
Unicode 18
Uniform Resource Location 77
uninterrupted power supply 158
UNIX 55
upper-CASE 149
URL 77
URS 141
Usenet 78
user interface 55
user requirement specification 141
utilities 67
Value chain 130
Value-Added Network 69
VAN 69
Vertical application 59
video projection 50
virtual company 109
virtual memory 66
virus 119
Visual programming 150
voice dictation 41
voice input 40
Von Neumann architecture 43
WAN 69
WAP 153
Web 77
web portal 109
web site 110
white box 26
Wide Area Network 69
Winchester hard drives 46
window 57
Windows 65
wireless 71
wisdom 19
Wisdom 19
word processor 5
Workstations 37
World-Wide Web 77
WWW 77
X.25 73
X.400 73
XML 152
X- Windows. 57
Zachman Framework 131
Discovering Information Systems
163
Live Music
Archive
Librivox
Free Audio
Metropolitan Museum
Cleveland
Museum of Art
Internet
Arcade
Console Living Room
Open Library
American
Libraries
TV News
Understanding
9/11